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Units in m 

'SourceiFT 12 ■ 


(excluding 


s ystemsl 


Volume 6 Issue 1© 


October 1983 


to#* 


^ Special issue — VDUs and graphics 

Inside Iks Advance — j an IBM for under £4@0? 

Acorn's Electron — a chip off the BBC block 

CF/ifi Plus, Atari writer! lte®©n fames 


Denmark DKr34 r 50, Greece Dra245.00 h Holland DFL3.50, Italy L4100, Spain PtsiMUK), Switzerland SFr7-40, Germany DM8.50, France Fr3Z60, Canada C$4,50 n 

Australia AS3.00, Singapore M$6,35 . r / 








Disks 


If you've ever lost data due to a faulty disk, you know how 
important reliability can be. 

That's why Accutrack disks are critically certified at 2-3 
times the error threshold of your system. Why they're 
precision fabricated for higher signal quality, longer life and 
less head wear. And why we take such extra steps as testing 
single-density mini disks at double-density levels. So you don't 
have to worry about the reliability of your media. 

Accutrack disks. OEMs have specified them for years. You 
can trust them for your data. 


Distributed in the United Kingdom by: 

Penbie International (C.A.) Ltd. 

23 Addington Road 
Reading RG 1 5PZ 
Berkshire 
Tel: (734) 664361 

m ACCUTRACK 

l£lfj Dennison KYBE (UK) 

9 Colonial Way 
Watford WD2 4JY 
Tel: (923) 50596 
Telex: 923321 

Offices and representatives worldwide 


• Circle No. 101 


LIST 



>NEWS 


| C HARDWARE NEWS 

■ft W Spectrum microdrives 
arrive at last. Newbrain in trouble, 
plus Apple plotter. 

| SOFTWARE NEWS 

A A Apple launches a new DOS, 
and Olivetti comes in from the cold. 

Ul IBM PC NEWS 

W A PC dongles from Wordcraft, 
and a glut of RAM expansion cards. 


>REVIEH5 


1BM PC XT 

QU DESK TOP TEST 

Part 3: the features of DOS 2 and 
running software on the hard disc, 

£*J | 16-BIT REVIEW 
U** LOGICA VTS 

Chris Bidmead checks out a British- 
made micro designed for office use, 

ACORN ELECTRON — 
"fOO A BBC KILLER? 

v Is Acorn's £199 offering compatible 
enough, and versatile enough, to 
replace the BBC Micro? Neville 
Maude reports. 


RA THE ADVANCE — 

A £i AN IBM PC KILLER? 

Ian Stobie previews a new British 
machine promising IBM PC 
compatibility starting from around 
£350, 



investigate the new Digital Research 
replacement for CP/M 2,2, 

©Q DRAGON GAMES 

Ptt We tried two dozen 
awful games for this popular micro, 
lan Stobie reports on the best of a 
bad lot, 

PRACTICAL COMPUTING October 1983 


Qf* HOME WP —PART 7 
OU ATARI WRITER 

Word processing on ROM for the 
Atari 400 and SGG, tested by Jack 
Schofield. 

1 <19 IBM PC B00KS 

A A Books for the PC are 
coming out fast. Jack Schofield 
reviews a baker's dozen. 


>VDU'S AND 
GRAPHICS 


A4 SETTING 
90 THE SCREEN 
An introduction to this month's 
special topic, computer graphics and 
things to display them on, 

©y| VDLIs, MONITORS 
9“* AND TV SCREENS 
Chris Naylor describes how visual 
display units work, and the 
advantages and disadvantages of TVs 
and monitors. 

1 AO YOUR GUIDE TO 
IVA GRAPHICS 

John Lewell looks at recent 
developments in computer graphics 
and provides an overview of the 
market. 




GEOMETRICAL 
PLOTTING LIBRARY 

Jonathan Bowen's routines can be 
used for graphics drawing in almost 
all versions of Basic. 

1 O ari a HI LING ’ ' 
?fM‘ 1 A ON THE BBC MICRO 

John G Dallman reveals some 
sophisticated area- fill techniques for 
the BBC computer. 

1 1 C DIGITISING 
A O CAMERA INPUT 

Peter Kruger and Stephen Cronk of 
Digit hurst describe how pictures can 
be converted into screen graphics 
using low-cost image-analysis 
techniques. 



FEATURES 

Qf* PC s BIG GAME HUNT 
^•9 Rate your favourite game 
and send It in for our Special Games 
Issue in December. 

1 1 O FICTION — DEATH 
HO TO THE MACHINE 

144 STATISTICS — 

Ififil COFFEE, TEA OR? 

Survey a range of choices: when do 
the results become meaningful? Owen 
Bishop explains. 

sAoft education — 

MSI fiO CASH REGISTER 

Commerce comes to the classroom in 
Hewan Ormson’s interesting 
programs. 

4A APPLICATIONS — 

V POST CODES 

Post codes can be a profitable key for 
mailing iist/address sorting. 

REGULARS 

E EDITORIAL - ONE MORE 

9 MICRO MAGAZINE 

The launch of Computer Choice , and 
thoughts on the choice of magazines. 

iy FEEDBACK 

M YOUR LETTERS 

Correspondence, corrections, love 
letters and advice. 

AQ CHIP-CHAT 

»9 Ray Coles on networks which 
use public telephones. 

4B RANDOM ACCESS 

O*# METAMATHEMATICS 

Boris Allan continues his discussion 
of threaded interpretive languages. 

OPEN FILE 

PROGRAMS 

Sixteen pages of free software for 
Apple, BBC, Sinclair, and other 
popular micros. 

IVA LAST WORD 
/>|* A 9 OBFUSCATION 

Why use one word when ten will do? 
Chris Naylor tells you how to master 
TechnoSpeak. 


This month's cover illustration was 
created by Steve Miller and Ian 
Stobie using a Hewlett Packard Series 
200 Model 16 with HP-7470 A plotter. 








WITHOUT KEYSTAR THE USER HAS TO FIND THE CORRECT KEYING SEQUENCE 
AND OPERATE A COMPLEX COMBINATION OF KEYS. 

Dear mlU / 

(SB- • 

1 ^, - 

f jy -cent v^W scuss .out £ 


' 


KEYSTAR WORKS AT THE PRESS OF A SINGLE, CLEARLY MARKED KEY. 


Keystar' puts editing on Wordstar 1 

into plain language. 


Tf 




Is your secretary the only person in your office who can 
talk to your word processor? 

Wordstar is by far the most popular word processing 
program available. But like all such systems, it takes time and 
practice to learn its language. 

Keystar now puts the whole office on speaking terms 
with Wordstar. Good news for those of us who have to work 
late on that vital report. And for the temp who started 
yesterday. (We like to think that it will also 
add a whole new dimension to your 
secretary's relationship with 
Wordstar.) 

Keystar makes Wordstar 
immediately accessible by providing 
fifty-six of its editing commands as 
colour-coded buttons, each labelled in 
plain English. 

Press the appropriate Keystar 
button; Wordstar performs 
as commanded. And since 
there is no need to display 
help menus, there is fifty 
per cent more room on 
the screen for your 
documents. 

Make Wordstar work 
for you! Contact your nearest 
Keystar dealer or order direct by 
completing and returning the order coupon. 

For the technically minded. Keystar connects easily to 


your microcomputer via an RS232C/V24 serial port. This 
port can be shared with other devices and on some systems, 
for example, Cromemco and Altos the device would naturally 
be the V.D.U. 

On integral systems, e.g. Apple II. Osborne, RML380Z, 
Superbrain, Act Sirius/Victor 9000, IBM PC, the device could 
be a printer, a plotter or a modem and special instructions are 
provided to direct Wordstar to recognise the presence of 
Keystar on such systems. 


TO: WMl PRODUCTS. INTEGRATED MICRO APPLICATIONS LTD.. 
21 LANSDOWNE CRESCENT, EDINBURGH EH12 5EH 


V 



Please se n d me K ey star u n its at £23 1 .75 p er unit 

(price includes VAT. carriage and insurance). 

I will be connecting Keystar to a 

microcomputer. 


1 enclose a cheque/postal order for £ 
to ‘WMl Products/ 


. made payable 


Please debit my Access Card No 
^ Visa Card No . 


. for £ . 
for £ 


Signature 


Name 


Address 


. Tel. No. 


Dealer enquiries welcome. Telephone 031 -225 3141 ask for Jim Wheatiey, 

Please allow ZB days for delivery. VAT No, 270709925, 

integrated Micro Applications Ltd reserve the right not to accept any order. Any acceptance will be 
subject to Integrated Micro Applications' terms and conditions. 

Wordstar is a registered trademark of Mieropro Corporation International. 

• Circle No. 102 



Editorial 



EDITORIAL 01-663 3609 
Editor 

Jack Schofield 
Deputy Editor 
Bill Bennett 
Assistant Editor 
ian Stobie 
Art Editor 
Sieve Miller 
Production Editor 
John Liebmann 
Sub-editor 
Sally Clark 
Editorial Secretary 
Sue Jordan 

Consultants 

Chris Bidmead 
Peter Laurie 

ADVERTISING 01 661 3612 
Advertisement Manager 
Ian Carter 01-661 3021 
Assistant Advertisement 
Manager 

Kenneth Walford 01-661 3139 
Advertisement Executives 
Lynne Brennan 01-661 3468 
Robert Payne 01-661 8425 
David Honeyman 01-661 8626 
Advertisement Secretary 
Janet Thorpe 
Midlands office; 

David Harvett 021 356 4838 
Northern office; 

Geoff Aikin 061-872 8861 
PUBLISHING DIRECTOR 
Chris Hipwell 

Published by Electrical Electronic 
Press, Quad rani House, The Quad rani, 
Sutton, Surrey $M2 5 AS. Tel: 01 -661 
3500. Telex -grams 392084 BiSPRS G. 

Distributee by Business Press 
International Lid. Quadrant House, 
The Quadrant. Sutton. Surrey SM2 
5AS. 

Subscriptions: LUC £13 per annum; 
Overseas £19 per annum; selling 
price in Eire subject to currency 
exchange fluctuations and VAT: 
airmail rates available on application 
to Subscription Manager. Business 
Press International Ltd, Gakfield 
House. Perrymount Road. Haywards 
Healh. Sussex RH16 3DH. Tel: 0444 
4591 88, 

Printed in Greal Britain lot the 
proprietors Business Press 
International Lid by Eden Fisher 
(Southend) Lid. Southend-on-Sea. 
Typeset by Centrepoint Typesetters. 
London ECl. 

Business Press International Ltd 
1983. 

Would-be authors are welcome to 
send articles to the Editor but PCcan- 
not undertake to return them. Pay- 
ment is at £35 per published page. 
Submissions should be typed or 
computer printed and should include 
a tape or disc of a ny program, Ha nd- 
written material is liable to delay and 
error. 

Every effort is made to check articles 
and listings but PC cannot guarantee 
lhal programs will run and can accept 
no responsibility for any errors. 


Overkill 


ONE of the moans that issues from these 
of rices is that there are too many micro- 
computers, One of the moans of the micro 
manufacturers is that there are too many mag- 
azines, They do not have time to read them, and 
do not know where to place their 
advertisements. 

Of course both moans are sweeping 
generalisations, and all generalisations are 
false. There may be too many badly designed 
micros, but there is still room for a few more 
good ones. Similarly there may be too many 
magazines, but there is surely a market for one 
or two more with something new to offer. 

With this in mind we are currently planning a 
new magazines called Computer Choice, which 
will be edited by Practical’s soon to be former 
deputy editor, Bill Bennett. It will deal 
exclusively with micros costing less than £200. 

The last bookstall magazine launched from 
the Practical Computing office was Your 
Computer. Its brief was lo concern rate on the 
home/games market, leaving us free to focus 
on the more serious side of computing. With 
the boom in the home market Your Computer 
has grown to be the U.K.’s largest selling micro 
magazine — by a wide margin* 

Practical Com put mg *$ c ircu latio n h a s g ro w n 
by a mere 25 percent over the last six months. 
The audited average sale for the six months 
from January to June was 61,1 00 , though 
recent issues have sold more. 

Naturally we are delighted with this response 
to our efforts, if only because it proves there 
are people out rhere who are interested in more 
than just space invaders. Needless to say we 
will try to make the magazine even more useful 
and informative in the future. 

Normally we do not boast about our small 
successes, but the margazine market is 
becoming very competitive* With new micros 
being launched there are always new potential 
readers and new potential advertisers. Almost i 
by definition they start from a position oT 
ignorance. 


Some companies, even big companies, know 
so lilt le about the micro world they do not even 
know how little they know. Advertisement 
managers in companies and in agencies, 
however, often seem to go from ignorance to 
arrogance in about 15 minutes* They are taken 
in by unaudited magazine circulation claims 
that stand no chance of ever being attained* 
Slick promotional brochures and cut-rate 
bargain offers must account for the bizarre 
media buying of some companies* Others can 
only be put down to naivety, We sometimes 
wonder why we bother producing magazines 
when we could be selling these people Tower 
Bridge or the crown jewels* 

The things they say make us laugh. If you 
owned one of their micros or were employed 
making them they might make you cry. The 
reason is that in the next few years some 300 of 
the 400 companies making and/or distributing 
micros in the U.K, are likely to be taken over or 
go out of business. Designers and product 
managers will wonder where they went wrong, 
after all, their micro was as good as, or better 
than, the next one — right? They spent enough 
money on promotion — right? So why didn't 
they sell? Well we know the answer already, but 
in this case there is little joy in being wise before 
the event. 

The forthcoming shake-out of manu- 
facturers will lead to a shake-out of magazines, 
partly because not all of that misplaced 
advertising will be paid for. Also, the more 
aware companies will start to gauge the 
response they get to their advertisements, and 
— at last — the number of leads that are con- 
verted into sales. The many worthwhile mag- 
azines, including Practical Computing , Your 
Computer and, we trust, Computer Choice will 
continue to prosper while the rest quietly slink 
away. 

All this will make the world a more reliable 
but, some would say, a duller place. We do not 
agree. Microcomputing is never going to be a 
dull subject, Q 


I II II 
1 I 

G | G (I Q GlH G P H 0 0 i 

1 IS 1 1 t : I J < ' J . "4 I 


I IK I I I 


II 


HUH 


| H U n u .: I u 


5 Years ago . . . 


; ’J i j 3 & p d n o ■. -i *i ■! ■( i * 


A hobby computer just coming to the market in the U.K. 
is the Sorcerer. It is made by the American firm, Exidy 
Inc, a video games manufacturer. 

The main selling point of the Sorcerer is price. You can 
buy a 16K version for £760 or a 32K version for £950 and, 
considering its facilities, this represents good value for 
money. 

The system loaned to us was the 32K version. 

Standard configuration includes a 61 -key typewriter 
keyboard and a 16-key pad. It looks like the Tandy 
keyboard without the numeric pad. To that you add your 

mm i |m 3 m s |m |: ? r* m a v Is ||m . i m m p 

I 7 1(11 I 1 T ia •- 1 ? .) ii mi id ,a 7 1 .■/ ii ’Vis fS r \ ii n 3 js . _•> :,n ij.vir K ** 1 H ‘.i ?r i-‘ ii tft 


! l) D II E n A 5 E-B a ft.™ 0 0 B U 0 a 0 .d fill B 0 0 
l * ‘n*- > - ■■ ■■ .“iJE H'txii'uti « ?■ n nil ri ff 

own power supply, TV monitor and cassette tape 
record er(s). 

For expansion purposes it takes the S-100 bus which 
gives you the ability to interconnect large memories, disc 
drives, speech and communications facilities. 

The striking feature of the Sorcerer, though, is the way 
you load the Basic .If s a standard Basic which is loaded 
by way of a cartridge into the side of the keyboard. It 
looks rather like an eight-track stereo cartridge but inside 
is a ROM containing the language. 

Practical Computing Volume L issue 4 


i* ?■ •* i’ ■< >■ - *r 


PRACTICAL COMPUTING October 1983 


5 


WATFORD ELECTRONICS 

33 (PC) Cardiff Road, Watford* Herts, England 
Tel Watford (0923) 40588. Telex: 8956095 


ALL DEVICES FULLY GUARANTEED. Send Cheque, P.O.s, Cash, Bank Draft with 

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4W2GLS31C 
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AY 5 101 3 
AY 5 1350 
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AY 5 3600 

COMBO 1 7 
COMB1 16 
DM6131 
DP03O4BN 
DS369 1 N 


225 
125 
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£25 
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426 

300 

100 

110 

2BO 

220 

270 

060 

255 

466 

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C95 

400 

395 

C40 

£17 

385 

450 

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3B5 

350 

£17 

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150 

120 

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90 

96 

550 

220 

125 

129 

£300 

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370 

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388 

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750 

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700 

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250 

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D$S03O 

H6 

DS&831 

135 

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250 

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£36 

ES366 

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FD1761 

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FD 1 7 7 1 

CIS 

F01791 

C32 

FD1793 

£23 

FD1795 

£28 

FD1707 

£20 

IM6402 

3BD 

INSB060N 

1050 

INS51 54 N 

£9 

MCI 4530 

5S 

MCI *89 

55 

MC 1 44 1 1 

696 

MCI 44 12 

725 

MC34*6 

210 

MC0447P 

316 

MC2486 

175 

MC34E7 

175 

MCSS4B 

625 

MK08B&-2 

C7 

MM520OD 

60S 

MM5303 

S35 

MM5307 

1275 

MM5357A 

475 

MM 00 174 

700 

00 3 251 3L 

56Q 

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566 

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006 

0F625GAL2 


TMS271B3 

lii 

TMB4164 1& 

475 

TM54500 

t14 

TM54032 

360 

TMS5100 

600 

TMS441& 

456 

TM58S27 

£14 

TMS9929 

£10 

TMS9395 

£12 

ULN2003 

75 

UPD7002 

426 

Z30CPU2.5 

285 

Z80ACPU 

300 

Z80B 

876 

2S0CTC 

250 

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200 

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405 

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800 

20ODMA 

675 

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095 

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260 

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300 

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130 

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410 

2N429EB 

210 

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070 

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200 

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605 

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656 


74S Series 


74000 

74SG2 

74003 

74&08 

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74S1 1 

74020 

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40244 
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45106 


330 

290 

296 

130 

105 


100 

225 

240 


196 

195 

166 

245 

595 


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MICRO leaflet. 


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yrswarri £20 

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Warranty] 

10x51" SSSD £ 1 8; DSDD £30 10x8" 
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' Circle No. 103 


6 


PRACTICAL COMPUTING October 1983 





Feedback 


Pascal 

semicolon 

IN your JUNE 1983 issue, page 7, John Robinson writes that the 
statement 

if x = y then if w = z then a: = 1; 
else b: = 1; 

is a correct Pascal statement. This is not true, see the book by 
Jensen- Wirth, Pascal. User Manual and Report , page 26, 
“Caution: there is never a semicolon before and else.” Hence, the 
text: 

jf p then begin SI; S2; S3 end; else S4 
is incorrect. Perhaps even more deceptive is the text: 
jf p then : begin SI ; S2; S3 end 

Here, the statement controlled by the if is the empty statement 
between the then and the semicolon; hence, the compound 
statement following the if statement will always be executed. 

The syntactic ambiguity arising from the construct: 
if < expression-1 > then if < expression-2 > then < statement-1 > 
else < statement-2 > 

is resolved by interpreting the construct as equivalent to 
jf <expression-1 > then 
beginjf < expression-2 > then < statement-1 > 
else < statement-2 > 

end” 

Hence, the correct form of the statement above is: 
if x = y then begin if w = z then a: = 1 end 
else b: = 1 
or 

ifx = ythen begin if w = z then a: = 1 ; end 
else b: = 1; 

In the second case, there are two statements between begin and 
end: the statement if w = z then a: = 1 and an empty statement. In 
both cases, there is not a semicolon after b: = 1 because “Pascal 
uses the semicolon to se perate statements, not to terminate 
statements; i.e. the semicolon is NOT part of statement.” Jensen- 
Writh, Pascal. User Manual and Report , page 22. 

Katalin Bauer, 
Budapest, 
Hungary. 


Formcalc 

Brian law’s excellent program 
in the July and August issues is 
going to be very useful to me. 
However 1 have two difficulties. 

First, in the example shown in 
the article when entering the 
formula shown under the RF 
command — I summed column 
l(Load) first — results in 
Error 2/1650 repeatedly. 
Formulae of the type 
Kl*K2*K3/4 work very well, 
but as soon as I use pow- 
ers in something like 
K 1 *(K2* * K3)/4 — again 
meaningless except as an 
example — I get Error code 
C/1650. 

Cursor shift 8, column shift 
to the right, does not work but 
cursor shift 5, to the left, does. 

Can you throw light on this 


for an elementary programmer 
like me? Incidentally, I have 
altered line 2305 to give results 
to four decimal places — it 
works very well. 

Leon Jeavons, 
Birmingham. 

Brian Law replies: 

It is difficult to debug programs 
without having the tape itself. 
The most likely explanations 
are: 

• line 1840 probably has the ** 
missing; 

• line 1310 probably has = “B” 
instead of = “8” 

Changing the number of 


decimal places can be done on a 
more permanent basis using the 
amendments below. To change 
the number of places now, enter 
DP3 to get three places of 
decimals, or DP4 to get four, or 
DPO to get none, etc. 

Basicode plea 

i would like to draw everyone’s 
attention to a new Basic 
language called Basicode-2, 
which creates a way to exchange 
software between different 
computers. The computers are 
Apple II, BBC Micro, 
Commodore Pet 2001 and 
Vic-20, CP/M systems, DAI, 
Exidy Sorceror, Ohio 
Superboard, Philips P-2000, 
Sharp MZ-80, SWTPC-68000, 
Tandy TRS-80 and Video 
Genie. 

The Basicode-2 language 
contains statements which are 
the same for all the computers. 
By using a translation program, 
which is different for all of 
them, your micro can 
understand them. If you have a 
program in your own Basic you 
can change it to Basicode-2 by 
using another translation 
program; so by using this 
language you can share your 
neighbour’s programs. I think 
Practical Computing should use 
Basicode-2 in Open File so more 
people can use the programs. 

Basicode-2 has been 
developed by NOS Hobby- 
scoop. It has a program on 
Radio Nederland every Sunday 
evening from 19.15 to 19.45 on 
747KHz medium wave, and 
each week it broadcasts a 
Basicode-2 program. You can 
order the translation programs 
and some Basicode-2 programs, 
plus a manual for 30 florins — 
about £6. The address is NOS- 
Hobbyscoop, PO Box 10, 1200 
JB Hilversum, Nederland. 
Alternatively write to me. 

Michel Smit, 
Zwaagdijk 152D, 
1683 NN Zwaagdijk-oost, 
Nederland. 

The editor replies: 

The manual is in both English 
and Dutch. Basicode is also 
used by Jonathan Marks on his 
English-language programme. 
Media Network, broadcast on 


Thursday nights on the Dutch 
International Service, and 
rebroadcast on the short wave 
world wide. So far 1200 baud 
has proved too much for short 
wave use, and experiments are 
continuing at 300 baud. For 
details contact Jonathan Marks 
at Radio Netherlands, PO Box 
222, 1200 JG Hilversum, The 
Netherlands. 

Incidentally, payment for 
Basicode must be in Dutch 
Guilders and payable to Nos 
Algemeen Secretariaat. The 
book and cassette weigh 370g, 
so send 25florins plus app- 
ropriate postage. 

Practical Computing has 
followed the progress of 
Basicode with interest, but we 
have had no requests for 
coverage from outside the 
Netherlands. Open File 
programs would be easier to 
translate if people wrote more 
structured programs with 
sufficient REM’s to give 
outsiders a chance. However, 
machine-specific tricks seem 
more popular. 

Calculating PI 

l write with reference to R A 
Fairthorne in the Feedback 
section of the August issue. He 
seems to have taken my 
criticism, which I hoped was 
constructive, to heart. I was 
merely wondering why he 
wishes to approximate PI using 
such a long and tedious 
division. 

Perhaps there is something to 
be gained from using his 
method, an unforseen ad- 
vantage. It may be faster, 
depending on the computer he is 
using, but I think I would rather 
enter the value of PI directly 
than use his division. The 
advantage of using my method 
(4^ATN (1)) 

is that it is easy to remember and 
will evaluate to as many places 
as the computer can handle. 

Perhaps you could have a 
competition to find the fastest 
and easiest method of 
calculating PI? Does anybody 
know what the exact value of PI 
is? 

S Mehew, 
Lanarkshire, 
Scotland. 

Reader survey 

i am writing to you for 
assistance in writing a series of 
articles to illustrate how micro 
(continued on next page ) 


Formcalc. 

2b LET DP=2 

296 IF 1«(1 TO 2) »"DP" THEN GOTO 2500 

2305 PRINT AT R1 +2, C (V) ; ( INT (Q <R, C) * ( 10**DP> +. 5) / ( 10**DP> 
2405 PRINT AT 20, C (V) ; ( INT <Q <N,C> * < 10**DP) 5) / < 1G**DP) 

2500 REM CHANGE DECIMAL PLACES 
2505 LET DP=VAL II- (3) 

2510 GOTO 1315 


PRACTICAL COMPUTING October 1983 


7 



Feedback 


I (continued from previous page ) 
computers are playing an 
increasingly valuable role as a 
low-cost aid to management 
and as fast information 
providers. 

Can 1 ask readers to write to 
me with their experiences of 
installing a micro at work, be it 
a ZX-81 or an IBM. What 
problems have they en- 
countered in software and 
hardware? Did the salespeople 
know what they were selling? 
Did, and was the buyer aware of 
the limitations of the computer 
he was being offered? Was the 
software adequate for the task it 
was bought for? If not, what 
difficulties were encountered to 
get the software or hardware 
working correctly? 

What questions, in hindsight, 
would readers ask the 
salesperson if they had the 
opportunity to purchase again? 
Finally, and I think most 
important, what benefit have 
they received by installing a 
micro? 

I would be most grateful to 
readers if they would write to 
me, all replies will be 
acknowledged by return of 
post. 

Tom Mcgowran, 
Monmouthshire Beacon, 
50, Monnow Street, 
Monmouth NP5 3XJ. 

Epson solution 

in his article on the Epson 
FX-80, August issue, page 77, 
Chris Roper mentions the 
warning in the Epson manual 
about control codes that cannot 
be sent out by certain versions 
of Basic. Chris points out that 
Epson do not propose a 
solution to this problem. 

The authors of the Epson 
manual must have had in mind 
such quirks as CHR$(9), which 
Microsoft Basic interprets as a 
tab character which it expands 
to a string of spaces. 

The solution is easy, at least it 


is if you are using an RS-232 
interface with mark parity. You 
simply set the high-order bit of 
the control character to one. 
The easist way to do this is to 
add 128 to the number. Thus 
CHRS(9) becomes CHR$(137). 
The Basic interpreter does not 
recognise this as a tab; the 
interface strips the high-order, 
parity, bit; and the Epson, or 
other output device, receives 
CHR$(9) — so everyone’s 
happy. 

Mike Lewis, 
London NW3. 

Keen on sprites 

in your JULY issue you gave a 
very useful program for editing 
sprites on the CBM 64 called 64 
Sprite Editor. Being somewhat 
of a novice myself I was keen to 
utilise this program as very few 
magazines seem to publish, little 
if anything for the 64 anyway — 
hint, hint. 

I did everything to the letter. 
That is, I turned the computer 
off and on, entered 
Poke 2560,0 Poke 44, 10 return 
and started typing from line 30. 
Flowever, immediately on 
pressing return after finishing 
line 30, the thing just crashed 
and the keyboard was 
completely disabled. 

I blamed myself for this error 
and tried again — and again and 
again, repealing the instructions 
as per Mr Irving’s article. Still 
no luck, so am I to blame or is 
there something else Mr Irving 
should have mentioned? Can 
you help — please. 

Finally, 1 enjoy your 
magazine but you seem slightly 


biased towards BBC, Tandy, 
Apple, etc. 

E G Reynolds, 
Lancashire. 

Blunders 

in THE ARTICLE on pro- 
gramming sprites on the 
Commodore 64, in page 99 of 
the July issue, we unfortunately 
missed out two important 
instructions. The two Pokes 
entered after turning the 
machine on should be followed 
by New < Return > . 

We would also like to repeat 
that lines 10 to 23 must be typed 
exactly as listed, the important 
feature being the number of 
characters entered. In the 
August issue. Atari Open File, 
page 145, line 32115 of Les 
Kneeling’s Slow Lister program 
should have ended “Poke 
842,12’’. 

Indian user club 

we have formed a home 
computer user’s club in India. 
We meet twice a month to 
exchange the latest news and to 
try and solve members problems. 
Owners/users of any home 
computer are welcome. We 
have developed a music 
program for the ZX-81 and a 
battery back up. In the near 
future we hope to bring out a 
64-column card for the ZX-81. 

Arun K Nath, 
New Delhi, 
India. 

BBC corrections 

i entered the disassembler 
program. Practical Computing, 
January 1983, in my BBC micro 
with the modifications printed 
in the March 1983 issue. I have 


two corrections to communicate 
to other readers. 

First, line 260 seems to be a 
little unlucky; it may have been 
printed a first time without a 
part and then wrongly corrected 
by M Cresswell in the March 
issue. The definitive — I hope 
— version will be: 

That is the 10th value has 4 
because the branch instruction 
set is printed with a 16-bit 
destination address. 

Secondly, the addition by E 
Ibbotson contains a mistake; in 
fact, line 1520 must end with 
MO$ = OS$(l%) 

instead of 

MO$ = 0$(l%) 

That is MOS must contain the 
name of the OS call, not the 
address. 

With these corrections the 
disassembler runs very quickly 
and with a very nice editing. 

P Jenne, 
Milan, 
Italy. 

Spectrum Scrabble 

in his review of computer 
Scrabble for the Spectrum, Bill 
Bennett expressed doubt on the 
validity of four particular 
words. 

According to Chamber’s 20th 
Century Dictionary, the 
national Scrabble champ- 
ionship’s standard reference 
guide, while “reiner” cannot be 
found, definitions of the other 
three read: 

agaze, (arch) adj. and adr. at 
gaze, gazing 

noon. — v.i. to rest at non. — 
n. nooning — (esp. U.S.) a 
repast or rest about noon. 

(continued on page 13) 


BBC correction. 

2!G0 DRTft 


•* , . 

■ 1 M Cl II 

t .* « • * I 


" & . . .. x 

it it o 

/ Cfc • i 

v 11 II ft 1* 

J i J Ob ■ a ■ • .* 



X" , . . 

V ii ii ji 


••a.... 

•• .. ■■ < & . 

**. v II ii / c* \ V 11 

■ -•* .» .» V. I I „» J 1 .« 



> " 









8 


PRACTICAL COMPUTING October 1983 





Two special offers... 
Six new software titles... 
Microdrive! 




Something 
for everyone, 
from Sinclair! 

Welcome to another 
Sinclair Special. Even if you’re not 
yet a Sinclair owner, I believe you’ll 
find something of interest in this 
latest issue. 

For instance, if you’re looking 
for the best way to begin computing, 
turn to our back page. You’ll see that 
leading Sinclair retailers are now 
offering the popular ZX81, complete 
with a 16K RAM Pack and a free 
software cassette, all for £45. That 
means savings of at least £29 on one 
of the world’s all-time best-selling 
computers. 

Those same retailers are also 
offering the ZX Printer at its regular 
price of £39.95, but accompanied 
by a free 5-roll Paper Pack, worth 
£11.95. 

If you want to add even more 
speed and versatility to your ZX 
Spectrum system, you’ll be pleased 
to hear that the new ZX Microdrive 
has now been officially announced. 

Microdrives are being released 
on an order of priority basis. 
Spectrum owners who purchased 
direct from us will be sent order forms, 
in a series of mailings that begin 
with the earliest names on our list of 
Spectrum owners. If you didn’t buy 
direct from us by mail order, send 
us your name and address (use the 
coupon in this Sinclair Special). 

We’ll add your name to the list, 
and send you a colour brochure 
and details on how to order. 

Finally, if you’re looking for 
more ways to use your ZX system, 
take a look at the software opposite. 
There are programs for programmers, 
a space-chase and car race for 
arcade-game players, a brand new 
logic game for those who've 
exhausted ‘the cube.’ 

The Cattell IQ Test is based on 
the definitive professional psychol- 
ogists’ test -and forms an accurate 
but easy way of measuring your 
own IQ. All the new programs are 
available direct from us, through the 
order form in this issue. 

You’ll see what I mean about 
Sinclair having something for 
everyone. And we'll have even more 
to show you at two forthcoming 
exhibitions: the PCW Show at the 
Barbican Centre, from September 
28th to October 2nd, and the Great 
Home Entertainment Spectacular 
at Olympia, from September 17th 
to 25th. 



Nigel Searle, Managing Director 
Sinclair Research Ltd. 


ZX Microdrive 
System preview! 



ZX MICRODRIVE 

At least 85K bytes storage, loads a typical 48K 
program in as little as 9 seconds: £49.95. 



ZX MICRODRIVE CARTRIDGE 

Compact, erasable, revolutionary. Complete with 
its own storage sleeve. Contains up to 50 files, 
with a typical access time of 3.5 seconds: £4.95. 



ZX INTERFACE 1 

Necessary for sending and receiving information 
from ZX Microdrive. Includes RS232 interface and 
local area network facility for 2 to 64 Spectrums. 
Attaches to the underside of your Spectrum. 
Purchased with ZX Microdrive, just £29.95. 

As separate item, £49.95. 








PSYCHOLOGY GRAND PRIX RACING, 
BRAIN TEASING, PROGRAMMING, 
SRACE-BLASTING! 

Sinclair have it all taped with six brand-new programs for ZX Computers! 


Chequered Flag 

For 48K RAM Spectrum. £6.95 

Have you ever wanted to drive a Formula 
One car flat-out round a Grand Prix 
circuit? With Chequered Flag you’ll 
need one eye on the road and one eye 
on the instruments, as you steer and 
brake to avoid hazards, and work 
through the gears in search of the lap 
or race record. This outstanding new 
program puts you in the driver’s seat 
with stunning realism, and gives you a 
choice of three cars and ten different 
circuits. Don’t crash I 


Zeus Assembler 

For 48K RAM Spectrum. £12.95 

A powerful and easy-to-use program- 
ming aid, designed to simplify the entire 
process of producing machine code 
programs, enabling you to write in 
assembly language instructions. 

Comes complete with comprehensive 
range of support facilities. 


Mothership 

For ZX81 with 16K RAM. £4.95 

Scream down the claustrophobic 
confines of the Zarway. Engage suicidal 
drone fighters in deadly laser combat. 
Dodge, duck and dive in a high-speed 
3-D race to attack the evil Mothership 
before she claims your home planet. 
Mothership is a truly tough challenge, 
and fast, furious fun! 


Monitor and Disassembler 

For 16K & 48K RAM Spectrums. £12.95 


Catteii IQ Test 

For 48K RAM Spectrum. £12.95 

Although there are a number of so- 
called self-administered IQ tests on the 
market, the only reliable way of finding 
your IQ has- until now- been to visit 
a qualified psychologist and take a 
battery of tests - for a fee. Now Victor 
Serebriakoff, International President of 
Mensa, has produced Professor Catteli’s 
test in a form which enables you to use 
your ZX Spectrum to test your IQ. 

The Cattell Scale MIA test is timed 
by the computer, marked immediately, 
and the marks standardised against 
your age. This is the first time that an 
accredited, standardised test has been 
available to the general public. 


Flippit 

For 16K or 48K RAM Spectrums. £9.95 




This powerful Disassembler translates 
machine code into comprehensibie 
assembly language instructions, 
allowing you to examine the BASIC 
ROM, to investigate the workings of the 
Spectrum or to analyse your own 
machine code routines. 

With the highly versatile Monitor, 
you get an extensive set of facilities to 
aid the entry, inspection, modification 
and debugging of your own machine 
code programs. 


Like those cube games, Flippit looks 
simple. But its fiendish ingenuity 
results in the ultimate game of logic and 
patience. Twist, turn and swap the nine 
Flippit pieces in search of the elusive 
magic square. But be warned, those 
pieces can be arranged in millions of 
combinations... 





TWO SPECIAL OFFERS FROM SINCLAIR 

STARTER 


PACK: 

£45 


Powerful passport to home 
computing -now at the lowest 
price ever! 

ZX81 


Sinclair 2X81 - 900 P 0G0 sold so far. 
Touch-sensitive keyboard . . . black and white 
graphics... just plugs into most TV sets. 

With 212-page BASIC manual -step-by-step 
guide to the world of personal computing. 
Normal price £39.95. 



ZX16K RAM PACK 


Gives the ZX81 more power- the power to 
run sophisticated software like Flight 
Simulation and Chess. Normal price £29.96. 


CASSETTE 


Worth £4,95 or more. In every starter pack, 
there's a top-flight 16K cassette -like Chess 
or Fantasy Games or one of the valuable 
education series. Actual title varies with avail- 
ability, And once you own your starter pack, 
there are 37 other Sinclair cassettes available 
(plus dozens from other manufacturers). 


ZX PRINTER AND 
FREE 5-ROLL 
PAPER PACK: 
£39.95 


ZX PRINTER 

Designed exclusively for use with the 
SinclairZXSI and ZXSpectrum persona! 
computers. Printing speed: 50 characters 
per second. 32 characters per line, 9 lines 
per vertical inch. Plus graphics direct from 
screen. Now with a free pack of 5 rolls of 
special paper (normal price £11,95). 


Look for the special 
packs at WH Smith, Boots, 

John Menzies, Currys and 
other leading Sinclair^— gg5 
stockists. Not Xytai pri e ®ii. 9 s! 

available by mail saves ^ 
order. 

Offers subject to availability while stocks last 



iini=laii- 


Sinclair Research Ltd, Stanhope Road, Camberley, 
Surrey, GU153PS. Telephone: (0276) 685311, 


How to order 


Simply fill in the relevant section (s) on the 
order-form below. Note that there is no 
postage or packing payable on Section B, 
Please allow 28 days for delivery. Orders 
may be sent FREEPOST (no stamp required). 
Credit-card holders may order by phone, 
calling 01-200 0200, 24 hours a day. 

14-day money-back option. ZX81 Starter 
Pack and Printer and Paper offers are not 
available by mail order. 


To: Sinclair Research Ltd, FREEPOST, Camberley, Surrey, GUIS 38R. 



ORDER FORM 

Section A: hardware purchase 



Section B: software purchase 




Gty 

Item 

Code 

item Price Total 
£ £ 

Gty Cassette 

Code 

Item Price 
£ 

Total 

t 


ZX Spectrum- 48K 

3000 

129.95 

FOR SPECTRUM 





ZX Spectrum - 16K 

3002 

99.95 

L4/S Monitor & Disassembler 

4403 

12.95 



Postage and packing: 

0029 

4.95 

L3/S Zeus Assembler 

4402 

12.95 





TOTAL £ 

G26/S Flippit 

4025 

9.95 



ZX81 Starter Pack and Printer and Paper offers are not available by mail order. 


PI /S Cattell IQ Test 


4500 


12 95 


Signature 


‘Delete/complete as applicable. 

* I enclose a cheque/postal order made payable to Sinclair Research Ltd for £ 


G31/S Chequered Flag 

4030 

6.95 


FORZX81 

G26 Mothership 

2125 

4.95 

J 


TOTAL £ 

* Please charge to my Access/Barclaycard/Trustcard account no: 

1 1 M 1 1 1 i 1 1 M 1 1 1 1 1 


; | ■ | , 1_J_ , . .1 j, . J 1 Mtiress I I I I J J_ _L ..1 _l L-L-L-LJ 

..... 1 I Mill: j 1 I Li I J — [ — I — J — J — ! — ! M I I I M PRCS10I 


' Circle No. 104 < Please prin,) 


ZX Microdrive information request 


Please add my name to the Microdrive Mailing List, and send me a colour brochure with full specifications 
of ZX Microdrive/lnterface 1 Q (tick here). You can use the above form to send us your name and address. 




Feedback 


Our Feedback columns offer readers the opportunity 
of bringing their computing experience and problems 
to the attention of others, as well as to seek our 
advice or to make suggestions, which we are always 
happy to receive- Make sure you use Feedback — it is 
your chance to keep in touch. 


(continued from page S) 

tyre — v,l to put a tyre on* — 

n. tyring 

Ian Tresman* 
Els tree, 
Hertfordshire, 

Bad timing 

it WAS wonderful to see that 
the Kewbrain was at last given a 
place in your excellent 
magazine. I, and many other 
Newbrain owners in this 
‘ country, sincerely hope that this 
will become a regular feature. 

L J Fotirie, 
Pretoria, 
South Africa. 

Logo 

i am preparing a book on the 
use of Logo in the classroom . 
i The book is primarily aimed at 
primary school teachers, but 
i will have some relevance to 
lower secondary school as well. 

1 would be very interested to 
hear of any experiences teachers 
have had using Logo in the 
classroom, and ways and means 
they employ to introduce the 
skills and concepts of 
computing to different age 
groups of children. This can 
include games, etc. All contri- 
butions will be acknowledged 
and postage refunded, 

A P Mullan, 
54 Copse Road, 
Plympton, 
Devon. 

Euromouse 

] am glad that my write up on 
the Computer Fair Euro mo use 
heats did not miss the boat 
entirely, despite its long delay in 
the post, 1 am sorry that it had 
to be cut down to fit the 
remaining space; particularly 
sorry that an acknowledgement 
I of the Judges 1 efforts did not 
appear. 

Professor Harry Prime of 
Birmingham University, 
Chairman of the Computing 


and Control Division of the 1EE 
did a splendid job of ensuring 
technological fairness. While 
Brian Glover, well known TV 
actor and the voice behind the 
Tetley Tea folk asked the 
contestants some searching 
questions, Chris Hipwell, 
publisher of Pracii ca / 
Computing * lent an air of 
authority to the judging. 

1 have already had an 
encouraging response to the 
announcement of a robot ping 
pong contest, which appeared in 
May 1983 issue of Practical 
Computing . Over two dozen 
letters have arrived including 
one from South Africa and one 
from Nato headquarters. They 
stress that their robot will not be 
an official project, nevertheless, 
if this letter is read by a robot 
enthusiast in the Kremlin we 
might see a needle match* 

John Billingsley, 
Portsmouth Polytechnic , 

Loading trick 

i MUST say how very much l 
enjoyed the maze program by 
Andrew Armstrong in the 
August issue of Practical 
Computing * There is no need, 
however, for you to exclude it 
from y on i g a mes -o ft h e-yea r 
disc. I find that a short loading 
program seems to do the trick 
without causing any problems 
Give the program a suitable 
name, for instance* Maze I and 
save it on disc along with the 
main maze program. To use, 
Chain “Mazer which will then 
automatically load then retook 
the main program* You will get 
an error message “Bad Mode at 
line 20“ . Ignore this, type Run 
and press Enter* The program 
should then run perfectly. 

I expect other readers will 
have devised other methods, but 
I hope you find this useful. 

R Dent, 
Harrow, 
Middlesex. E 


Loading trick. 

10 #KEY0 LG„ "MAZE" I M*TAPE12 [MF,T=0 TO TG 
R-PA6E STEP 4 : T ! &EOG=T ! PAGE: N. I 1 PAOE=&EO 
0 INRUN IN 
20 *FXI38 f 0 a 128 



Youre just 
one step away 
from one-^tep 
accounting 

Anagram Systems’ Integrated Accounts 
is. simply, the most comprehensive, 
easiest to understand integrated 
accounting package available to 
Commodore users. It is the best reason 
yet for choosing Commodore. 
j? And now ihere is Anagram Integrated 
Accounts with integrated Stock Control - on 
S top of superb Anagram standalone Stock 
Control and ledger packages. Just look at these features and 
options 

Full integration: Anagram Integrated Accounts consists of Sales, 
Purchase and Nominal Ledgers, Cash Book, and functions which 
permit lournal entries, file maintenance and report printing in 
remarkable detail All these are automatically updated when 
you make an entry In the version with Stock Control, creating 
an invoice updates the stock as well as the other modules. 
Single- or multi-user: Anagram Integrated Accounts, with or 
without the integrated Stock Control, can be supplied either 
single-user, or multi-user for up to five machines for only £300 
extra per machine. The same goes for Anagram Stock Control. 
Hard disk or floppies: Integrated Accounts is on just one floppy 
disk - compare that to competitive packages - and runs 
successfully with the Commodore twin disk units. Integrated 
Accounts with Stock Control and Sales Order Processing ideally 
requires a hard disk. 

Open Item or Balance Forward: Choose which system you want 
for each account - you can even mix the two 
Extensive analysis: Each sales invoice can be analysed across 
ten nominal headings; each purchase invoice across eight You 
can set up budgets within each nominal heading to get 
comparisons of budget to actual' at any time. 

Easy to understand* learn and use: Anagram 
Accounting and Stock Control packages are 
designed for busy people who don't want to 
mess about with computers. They use ordinary 
book-keeping terms without jargon. 

Your Commodore dealer should have these 
packages ready for demonstration. If not, phone 
Anagram and we will fix a demonstration for you. 

Or send the coupon. 



To: Actionline Sales 

Anagram Systems, GOA Queen Street, 

Horsham. West Sussex RH 13 SAD 


d 




% 

CD 


Send me brochures on ihe Anagram packages 1 have tacked and (ell 
me where to see them running 

]J Integrated Accounts with Stock Control 1 3 Integrated Accounts 
□ Standalone Slock Control □ Standalone Ledgers 


Name • 

Position 

Company 

Nature, of business . 
Address 


County 

Telephone No 

Any existing CBM computer . 


Postcode . 



=nnncRnm jvmms 

60A, Queen Street. Horsham, West Sussex 
RH13 5AD TeU0403) 59551' 50854/58153 


,1 u.nli-TTMtk -1 ■ "iitnilkK l"i** bunittrw. M.n'hnir-:. .IJKj 1-iU 


AN/PCQ i 10 


* Circle No. 105 


PRACTICAL COMPUTING October 1983 


13 



LONDON COMPUTER CENTRE 


SIRIUS 1 

1 .2 Mb Disk Storage £2195 
2.4 Mb Disk Storage £2695 
1 0. Mb Disk Storage £3995 



EPSON 0X10 

Multi Fonts 
Zoom 
Graphics 


NEC ADVANCED 
PERSONAL 
COMPUTER 

16 bit 8086 128K Ram 
2.4Mb Disk Storage 
CP/M86- MS DOS 

From £1985 


192K RAM 
£1735 

Upgradeable 
to 256K 


SUPERBRAIN 2 

Dedicated 
| Wordstar 
' Keypad 

from 
£1865 


New TANDY 
Model 4 

CP/M 3.0 
64K-128K RAM 

from £1299 



SENDATA 800 SERIES | 
ACOUSTIC COUPLER 
£220 

’ Compact, lightweight, portable 
* 10 hours operation from, the 
r&chargable batteries 
" 300 BPS answer/ofkjjnate 
' Handset sensor on/oft switch 
■ New crystal controlled 
circuitry 

* B-T. Approved. 


TELE-VIDEO 

806/816 

the Multi User 
Computer System 


PORTABLES 

EPSON TANDY 100 

■ j vaa Portable with built-in 

H A Mm U 4 Programmes; Word Processor, 

Portable with built- address book., scheduler and 

■ communications. Large 40x6 char, 

in p nnter i re display 

from £402 £433 


OSBORNE 1 



New ZORBA 


Double 

density 

£1350 



Portable 

full 80 x 20 


display 
BOOK disc 


storage 

€1595 


FLOWRITER 
RP 1600 
60 CPS 

Fast and reliable 
8K buffer 

£1600 


TECF10 
40 CPS 

Diabio 620 compatible 
Japanese reliability 

£1250 


New JUKI 6100 
Daisywheel 18 CPS 

Bi directional 
Adler 

daisywheels,; 

Diablo 630 
protocols £ 399 ' 



3 in One 

TOSHIBA 

P1350 


24 Needles - high speed 
drafts 190 CPS Letter Perfect 
Printing 100 CPS Addressable Pin 
Graphics €1130 Options: 

Tractor €87: Sheet feeder €520 


3 TRAY AUTO 
SHEET FEEDER 

For originals, 
copies and envelopes. 

£695 

SUITABLE FOR MOST DAISY PRINTERS 



EPSON 
FX80 
OCRS 


OKI 84 
200 CPS 


£850 


SINGLE 

SHEET 

FEEDER £375 


New SHINWA 
CP 80 MATRIX 
PRINTER 

80 CPS Friction and Tractor inc. 
interface cable and paper £250 


All prices are Exclusive of VAT and Delivery. Dealer Enquiries invited on all Products. 
Large range of CPM Software available. Please phone for Prices. 
Demonstrations on all models. 


43 Grafton Way, London W1P SLA (Opposite Maples) 

Opening Hours: 10-7 Mon-Fri. 12-4 Sat, 

01-387 4455 (4 lines) Telephone Answering Service After Office Hours Telex: 8953742 


• Circle No. 106 



Introducing The Tandy 
Micro Executive Workstation 



499 


8K RAM 

Cat. No. 26-3801 


■ Powerful Built-In 
Software 

■ Retains Memory 
Data When “Off’ 


■ 8K RAM- 

Expandable to 32K 


TEXT 


elect 


TELCQM a£i>r!s 


*±44$ Bytes free 


User Friendly Software 
Makes The TRS-80 
Model 100 Portable Computer 
Truly Revolutionary 

Imagine a computer on your desk so small, it can fit in 
your in-tray. The second you turn it on, imagine seeing a 
menu of built-in executive management programs and 
your own files, ready for immediate use. All revealed on 
an eight-line by 40-character LCD display positioned 
just above a full-size keyboard. And when you leave the 
office, imagine a four-pound computer you can take 
along, because it works on mains or batteries. 

Stop imagining! The new TRS-80 Model 100 is the 
computer you’ve been waiting for. As a desk organizer, 
it's a phone directory, address book and appointment 
calendar. It’s a personal word processor, as well. 
There’s even built-in communications software to 
access other computers by phone, using an acoustic 
coupler. 

Come and see the most revolutionary computer since 
the TRS-80 Model I at over 340 Tandy stores and 
dealers, including over 25 Tandy Computer Centres 
nationwide. • Circle No. 108 


Built-In Interactive Software 


WORD 

PROCESSING 


appointment 

SCHEDULER 



Pi 

. 1 





The Biggest Name 
in Little Computers 


| 1 

. Call In Today Or Send For Further Information | 

1 Computer Marketing. Tandy Corporation {Branch UK), Tameway Tower. . 
| Bridge Street, Walsall. West Midlands. WS1 1LA. 1 

| Name — ® 

■ Address . I 


P 1 7 J 










Please send me 
details of the ACT Sir ius 1 


f Name;. 

Position: 

Company 

Address;_ 


OVER 20,000 PEOPLE 
CAN’T BE WRONG 

ACT SIRIUS 1 


c£2,195 

£2,895 


Powerful 1.2Mb data storage with 128K 
RAM and including two of the industry 
standard operating systems at 16-bit level, 
CP/M-86 and MS-DOS. PLUS Basic 86. 


2.4Mb data storage with a big 256 K RAM for 
the really demanding business applications. 
Includes CP/M-86, MS-DOS and Basic 86. 


Above are two very good reasons why more people have bought the ACT Sirius 1 than any 
other 16-bit microcomputer in the U.K. Here are a few more: 

,S ‘YT perb user A riend !v ma chine incorporating a comprehensive 'soft' keyboard, 
■§ rc ^' L ' lo ( n s . f :T' e T ° r cmp ' c * ear definition and a wide range of memory options 
including a 10Mbyte Winchester version and a choice of three plug-in expansion boards. 

The range of available software is simply unrivalled in the personal computer field 
Over 1,000 software packages now exist to provide complete solutions to 
the needs of large and small businesses alike. 

Anl 0 ()fTmPl6 th h : t AC ^ SiriUS f 1 ' S batked by tbc stren « th and ^sources of ACT. The Pulsar 
‘ A , U b software for accounting, planning and word processing; ACT Training 

ntres open to all; nationwide field service; a full range of printers and consumables. 

And, the most complete and professional dealer network in the U.K. 

Over 20,000 people are rightly convinced that the ACT Sirius 1 is the best machine 

of its kind in the country. 

CAN YOU REALLY AFFORD TO BE WRONG ? 


ACT SIRIUS 1, THE UK’S BEST 
SELLING 16-BIT 4 

MICROCOMPUTER? 




• Circle No. 109 
P.C. OCT. 


ACT (UK) Limited 

Shenstone House, 

Dudley Road, Halesowen, West Midlands B63 3NT 
Telephone; 021-501 2284 
Telex: 337007 










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News: software 


Apple Prodos 


Apple are releasing a new 
operating system for the Apple 
II and He called Prodos. Aimed 
at the professional software 
developer Prodos resembles 
SOS, Sophisticated Operating 
System, as used on the Apple 
III. Prodos uses the same data 
formats as SOS and provides a 
similar Unix-like hierarchical 
file structure. 

Apple DOS will continue to 
be the standard Apple II 
operating system, but by 
releasing Prodos Apple are 
responding to the need for a 


better development en- 
vironment, Apple say Prodos 
allows larger file sizes, more 
efficient memory-management, 
better response times, and that 
it makes disc- based applications 
device-independent. 

Prodos will not be on general 
retail sale until early 1984, but it 
is available now to software 
developers under licence. For 
details contact Apple Computer 
(U.R.) Ltd., Eastman Way, 
Hemel Hempstead, 
Hertfordshire HP2 7HQ, 
Telephone: (0442) 60244, 0 




Micro replaces 
maths teacher 

Fun Mathematics on Your 
Microcomputer, is by Czes 
Kosnowski. The book discusses 
mathematical principles with 
lots of program examples and 
games written in a non-machine 
specific Basic. Published by 
Cambridge University press at 
£4.95, ISBN 0 521 274 516. □ 


Olivetti comes 
in from the cold 

MS-DOS can now be obtained 
along with CP/M-86 for the 
M-2G, Olivetti's heavily pro- 
moted 16-bit computer 
two operating system 
together with an 80S6 add-on 
processor card for a price of 
£200. With the card fitted the 
M-20 should be able to read 
IBM PC formatted discs. The 
MS-DOS is MS-DOS version 1 . 

The M-20 has until recently 
been out on something of a 
software limb. The system is 
built around the rather unusual 
2-8000 processor chip and 
comes supplied with an Olivetti 
own-brand operating system. 
The new processor card turns it 
into a more conventional 
machine costing, with the 8086 
card fitted, £2,695 for a system 
with twin floppy drives. 
Contact: British Olivetti Ltd, 
86-88 Upper Richmond Road, 
London SW15 2UR, Tele- 
phone: 01-785 6666, 0 

Last One cheap 
on Commodore 64 

The latest serious software 
product to become available for 
the Commodore 64 is DJ 'AT 


publicised 
program generator, The Last 
One, At £85, the price is lower 
than versions of the product for 
other machines, in line with the 
lower price of the 64 which 
doubles as a home enter- 
tainment machine. 

DJ ‘AT Systems has also just 
released The Last One for the 
Zenith Z-10G and the Hitachi 
MB- 16001 16-bit machines, this 
time at the more usual price of 
£330. Details from DJ ‘AF 
Systems, Station Road, 
Ilminster, Somerset TA19 9BQ. 
Telephone: (04605) 4117. [J] 


Ffosswriter 

Ffoss's Correspondent Word 
Processing package for the 
HX-20, the development of 
which we described in Practical 
Computing, March 1983 is now 
on sale. The name has been 
changed to Ffosswriter because 
of a name dash with another 
product, but it is the same 
ambitious package as described 
in the “Computing on the 
Train” feature. 

What distinguishes it most 
from other text -editing 
packages for the Epson is its 
disc-like random access 
handling of the HX-20's 
microcassette drive. It allows 
the user to operate conveniently 
with named documents and 
makes block copying operations 
between different documents 
possible. 

Supplied as a plug-in 
EPROM along with a 50- page 
reference manual, Ffosswriter 
runs on the HX-20 with or 
without the expansion unit 
fitted, and costs £95. Full details 
from Ffoss Ltd, 1 12 Bath Road, 
Slough SL1 3SZ. Telephone: 
(0753) 820277. 0 

Apple card 

Advanced Logic Systems’ 
CP/M Plus card for the Apple 
II and Apple lie is now 
available in the U.K. At £300 


the plug-in processor card is 
good value, it includes not only 
the new CP/M Plus operating 
system from Digital Research 
but also an extra 64K of RAM, 
CBasic, GSX Graphics, and 
various software utilities. The 
card uses the fast 6MHz version 
of the Z-80 processor chip. 
Contact Scope Systems, 13 
Carlisle Road, Queens Park, 
London NW6 6TL. Telephone: 
01-969 9365, 0 


Lots of art 
for the BBC 

BBC computer owners have two 
new drawing packages to chose 
from. Beeb-Art which is from 
Quicksilva lets you draw lines or 
shapes in any of the 16 Mode-2 
colours and save them to 
cassette. It costs £14.95 and 
comes on cassette for the BBC 
Model B, with or without 
joysticks. 

Easy Graphics from Hexagon 
Software is a similar package 
additionally featuring rubber- 
band line drawing. Costing 
£13.50, Easy Graphics also 
comes on cassette and runs on 
either a Model A or B machine 
with at least 32K of RAM. 
Joysticks are not required. 

More details from Quicksilva 
Ltd, Palmerston Park House, 
( continued on page 24) 



BCPL, Forth and Lisp — three of the languages with the biggest 
cult followings — are now available for the BBC computer. BCPL 
is a structured language widely used in universities as an 
alternative to assembler. Forth is becoming increasingly well 
known for producing fast, compact code, and is ideal for machine 
control and graphics applications. Lisp is a list oriented language 
much used for artificial intelligence research and writing expert 
systems. Lisp and Forth are available on either cassette at £16.85, 
or on disc at £19,90. The user guides cost £7.50 each, BCPL is 
more expensive at £99,95 for a pack containing the run-time 
system on ROM along with other parts of the system on dise and 
the user guide. The BCPL user guide costs £15.50 bought 
separately. More details from Acorusoft Ltd, 4 A Market Hill, 
Cambridge CB2 3NJ. Telephone: (0223) 316040. □ 




PRACTICAL COMPUTING October 1983 


21 





THINK 
SUPERBR 



Choosing SuperBrain is good thinking 
according to hundreds of happy users. 

It came out top in an independent survey by 
beating Apple III, Sirius 16 bit, Zilog MCZ 2 


USER BASE 

FUTURE 

A - fewer than 200 

Limited - uncompetitive. 

B - fewer than 500 

Reasonable - short life and competive 

C- fewer than 1000 

Good - remaining competitive and expandable. 

D- more than 1000 

Excellent - very competitive for many years. 


and others on price/performance rating, user 
satisfaction, user base size and prospects for 
the future. 

SuperBrain scored highest — or equal highest 
— in every respect. Its future was rated 
“excellent” — very competitive for many years. 

All this comes in a compact, single desk top 
unit. 




and we give you more 
with your SuperBrain 


SUPERBRAIN 


Hard Disk Upgrade 

An integral Winchester hard disk upgrade available. 
Encotel who pioneered this feature nave supplied over 
200 hard disk SuperBrain systems to companies 
throughout the U.K. 

Increase in Fast Access Storage Capacity 
E- Store 

Add-on Winchester disk sub-system designed and 
manufactured by Encotel the E-Store offers instant 
upgrade in storage capacity at low cost. The fitted 
Rodime disk comes in a range from 5Mb to 40Mb and 
plugs into many leading micros. 

Software 

The importance of well supported and commercial 
software has always been recognised by Encotel. 


A great deal of time and effort is spent in the 
evaluation of new packages before they are added to 
our product list. 

Over the years Encotel have been instrumental in 
bringing to the U.K. market a number of leading 
software products for SuperBrain. Our range is wide. 
There are five programs in the Microsoft range. 

Telex 

Pioneered by Encotel, the Microtelex unit turns your 
microcomputer into a telex preparation and handling 
unit with direct connection to the telex network. While 
you run your normal day-to-day application 
Microtelex automatically transmits your messages into 
the telex network — as well as receiving incoming 
messages — all in background mode program. 


Optional Resolution Graphics 

A choice of high or medium resolution graphics 
available. High resolution: 1024 x 512 Pixel graphics 
128K I/O Mapped. Price £660. Medium resolution: 
512 x 256 Pixel graphics 16K I/O Mapped. Price 


Rental Facility 

Encotel have a pool of equipment available for short- 
term rental at attractive rates. Minimum period is one 

week. 

The SuperBrain is available on this basis — rent starts 
at only £25 per week including printer. 

In addition, full leasing facilities can be arranged on all 
capital equipment 


SuperBrain Dealers 

MIDLANDS AND NORTHERN ENGLAND 

DUDLEY Independent Systems Ltd 0384 236934 
LEICESTER Scilex Ltd 0480 58022 
STOCKPORT Microscope 061-499 0431 
ST. NEOTS West Com Ltd 0480 217217 

LONDON 

NORTH LONDON Boyd Microsystems Ltd 01-950 0303 
KINGSTON UPON THAMES Ideal Computer Systems Ltd 
01 946 5568 

LONDON SW1 Direct Data Marketing Ltd (DDM) 01 834 5016 
LONDON W1 Bondbest Ltd 01 580 4273/7249 
LONDON WC2 Systematica Ltd 01 836 9379 


SOUTH EAST ENGLAND 

BRENTWOOD Direct Data Marketing Ltd (DDM) 0277 229379 
GUILDFORD AFK Associates Ltd 079 82 3758 
HORSHAM Sussex Microsystems Ltd 0403 68701 

WEST COUNTRY 

MELKSHAM Advent Data Products Ltd 0225 706289 

WALES 

GWYNEDD CP.L Ltd 075 881 2053 

IRELAND 

CASTLEBAR Delta Microsystems Ltd Castlebar 22632 
GALWAY Associated Micros Cork (021) 871669 
Galway (091) 68506 


SYSTEMS 


EMtOCOleL 

Britain s specialist microcomputer distributors 


ENCOTEL SYSTEMS LIMITED 7 IMPERIAL WAY 
CROYDON AIRPORT INDUSTRIAL ESTATE 
CROYDON SURREY CR0 4RR 
Tel 01 686 9687 01 680 6040 (six lines) 

Telex: 8951921 ENCO G 


ENCOTEL SYSTEMS (WEST) 

77 LALEHAM ROAD 

STAINES MIDDLESEX TNI 8 2EA 

Teh (0784) 63466 Telex: 932905 LARCH G 


• Circle No. Ill 



For LOW. . . LOW. . . LOW. . . prices 
you need only one number - 

0962 66191 

We have a surprise for you . . . 
an offer you cannot refuse!! 

Whether you need only a few diskettes or many computer systems, 
we can save you a great deal of time, money and effort . . . 
all you need is ONE NUMBER . . . 0962 661 91 . 

Why not call today and ask for a quote. 

We supply all major brands of computers, printers, diskettes, 
ribbons, etc. 



DISKETTES 

RIBBONS 

DAISYWHEELS 

FLEXYDISC BOXES 

CUT SHEET FEEDERS 

COMPUTER 

STATIONERY 

‘ Official order* accepted 

' Nationwide maintenance conlrati* 
ovaiJoble on most product*. 


PRIMERS 

EPSON 

STAR 

NEC 

TEC 

TEXAS 

ANADEX 

RICOH 

QUME 


COMPUTERS 

APPLE 

COMMODORE 

IBM 

SIRIUS 

BBC 

EPSON 

TEXAS 




50A Stockbridge Road , Winchester, Hants. 3022 6RL England Te! : Winchester (0962) 66191 


micro miracles 


t Circle No. 112 


BACK UP VISIC ALC 
AND ALL YOUR VISIS 
QUICKLY AND SIMPLY 


Ccopy ii plus} 

COPY 
COPY 

\ COPY . 


|[3aDC3QQQ 


Send cash with order, or quote your Access or Diners card number to: 

Orchard Software, 17, Wigmore Street, London W.l. Telephone 01-580-5816. Dealer enquiries welcome. 

• Circle No. 113 


Copy li Plus is a versatile software back-up system, capable of 
backing up all visls, as well as most other protected software. 

Its fast — only 45 seconds for Fast Copy, less than three minutes for 
Bit Copy. 

Its simple — menu driven for ease of use with full instructions on 
backing up dozens of popular programs. 

Its comprehensive — it includes all the file handling and DOS utilities 
you will ever need. 

Its priced right — at around half the cost of similar competing 
products. 

Copy II Plus — only £35 + v at. 


PRACTICAL COMPUTING October 1983 


23 









GRAPHICS - DATA CAPTURE - MEDICAL PHYSICS - VIEWDATA - 
SECURITY - FACSIMILE - DESIGN - PRINTING - BADGES - 
CONSUMER TEXTILES - ILLUSTRATION 



We captured this little manikin running to see a demonstration of the versatile 

DIPLOMAT VIDEO DIGITIZER 

£195 (Apple H -f) 

£345 (Apple / /e, includes 64K Extended 80 Column Card) 

Plus Carriage and VAT 



Details and demonstrations at PCW Show, Stand 345, Hall B, Lower Level (Pete & 
Pam) and COMPEC '83, Stand 718, National Hall (Computech), your nearest 
Apple Dealer, or the manufacturer: 

SYSTEMS 

1 68 Finchley Road London NW3 6HP 
Tel: 01 -794 0202 
Telex: 268048 EXTLDN G 



• Circle No. 114 


Just plug 
in a Sola. 


Sola Minicomputer Regulators and Mini UPS systems replace 
the dedicated line plus provide greater protection against 
power line disturbances 

FOR MORE INFORMATION ABOUT THE SOLA POWER 
PROTECTORS CONTACT: 


28 LURKE STREET 
BEDFORD MK40 3HU. ENGLAND 
PHONE 0234-40094 
TELEX 026431 


A UNIT OI= O r. M E « A 


Gc 

L SION At tj 


SOLA-BANNER 

[EUROPE] LTO 


• Circle No. 115 


News: software 


(continued from page 21) 

13 Palmerston Road, 
Southampton SOI ILL. 
Telephone: (0703) 20169. And 
from Hexagon Software, 17 
Straits Road, Gornal, Dudley, 
West Midlands DY3 2UR. 
Telephone: (0384) 232992. Q 

Sharp and Tandy 
statistical forecast 

Easi-Trend for the Sharp 
PC- 1500 and Tandy PC-2 
pocket computers enables users 
to identify trends and make 
forecasts from entered data. 
The program comes with a 
manual explaining statistical 
forecasting, and costs £19.95, 
including VAT. For more 
details contact Elkan Elec- 
tronics, 11 Bury Road, 
Prestwich, Manchester M25 
9JZ. Tel: 061-798 7613. Q 

Specific packages 
for Commodore 

Specific Software has released a 
range of tape and disc-based 
programs for the Vic-20 and 
Commodore 64 to do invoicing 
and sales and purchase 
accounts. Specific say the disc 
versions can handle 300 
accounts and up to 2,000 
transactions, while the cassette 





The new software package 
called The Word processor is 
not quite what it seems. It is the 
King James Bible on disc. The 
complete text is contained on a 
set of discs along with a 
program which lets you search 
the scriptures for any word or 
phrase you w ish to refer to. Ap- 
ple and IBM PC versions are 
available from Pete and Pam 
Computers at £149. Contact 
Pete and Pam Computers, New 
Hall Hey Koad, Rossendale, 
Lancashire BB4 6JG. 
Telephone: (0706) 212321. Q 


versions are good for 60 
accounts and 300 transactions. 

Prices range from £20 for a 
Vic-20 invoicing program to 
£150 for disc-based sales 
accounts with integrated 
invoicing for the Commodore 
64. Details from Specific 
Software Ltd, 10 Farlands 
Road, Stourbridge, West 
Midlands DY8 2DD. Tele- 
phone: (03843) 73377. Q 

Image analysis 
system on 
ACT Sirius 

Digithurst’s image-analysis 
system will now work with the 
ACT Sirius computer. The 
Microsight image-capture 
package consisting of video 
camera, interface box and 
software achieves a resolution 
of 256 by 256 pixels and costs 
£495. The Microscale software 
suite consisting of programs to 
manipulate images and measure 
perimeters and areas costs £295. 
Versions of the system are 
available for other micros 
including the BBC and Pet 
computers. Contact Digithurst 
Ltd, Leaden Hill, Orwell, 
Royston, Hertfordshire SG8 
5QH. Telephone: (0223) 
208926. Q 

Hewlett- Packard 
integrated packac 

MBA, the integrated 
spreadsheet, graphics and filing 
package from Context can now 
be obtained for Hewlett- 
Packard’s new 16-bit 
68000-based machine. Context 
MBA’s core function is a 
spreadsheet of 95 columns by 
999 rows. The user can enter 
text, numbers and formulae in 
any cell. As any cell can hold up 
to 8,000 characters MBA can be 
used as a database and as a 
simple word processor. The 
package allows you to do 
sorting and searching 
operations and to construct 
several different kinds of graphs 
from cell data. 

Context MBA is already 
available for the IBM PC, 
requiring the 256K RAM 
expanded system to run. The 
standard HP Series 200 model 
16 comes with half a megabyte 
of RAM and uses the powerful 
68000 processor, so it is well 
suited for this type of large, 


PRACTICAL COMPUTING October 1983 





Software dealer 
to join Softsel 

Software dealer SBD Software 
is to gradually stop trading. 
Susan Ben-Da vid, who owns the 
company, is closing it down and 
joining Softsel, the large 
American software distributor 
which has recently set up an 
operation in this country. Susan 
Ben- David's job as product 
services manager includes the 
task of selecting British and 
European software for 
distribution by Softsel 
worldwide. H 


More packages for 
BBC accounting 

Six disc-based business 
packages for the BBC 
Computer have been 
announced by HCCS, covering 
nominal, purchase and sales 
ledgers, stock control, order 
processing and payroll. Each 
package costs £59.95 and can be 
used on its own or as a module 
integrated with the other 
packages in the range. Details 
from Home and Continental 
Computer Services Ltd, 22 
Market Square, Biggleswade, 
Bedfordshire SG18 8AS. 
Telephone: (0767) 317300. Q 



mul ti-Fu net i on ge n eral p ack age . 
The HP keyboard’s unusual 
cursor-control knob can be used 
to scroll around inside Context 
MBA. 

Context MBA for the HP 
system costs £593 . A Model 1 6 
system with twin Sony 
microdrives costs £5,213, 
Details from Personal 
Computer Literature De- 
partment, Hewlett-Packard 
Ltd, Customer Service Centre, 
Winnersh, Wokingham, 
Berkshire RGI1 5DZ, 
Telephone: Crowthorne (0344) 
773100. Cl 


Which home computer gives 
you so much software for so little? 


Entertainment for all: 

Video Chess £34 95 

Munch man £29,9 5 

Parsec (Optional Speech) £29.95 
Othello £24,95 

Tu nnel s of Doo m £24.95 

Adventure Cartridge £24 95 

Additional Adventure Games; 

all at £14,95 

Adventure Land 
Mission Impossible 
Voodoo Castle 
The Count 
Strange Odyssey 
Mystery Fun House 
Pyramid of Doom 
Ghost Town 
Savage Island 
Golden Voyage 


Alpiner 


(Optional Speech) 

£24.95 

T1 Invaders 

£19.95 

Car Wars 

£19.95 

Chisholm Trail 

£19.95 

Hustle 

£14.95 

Tombstone City 

£14.95 

Connect Four 

£14.95 

Video Games I 

£14.95 

Hunt The Wumpus 

£14.95 

Five-A-Side Soccer 

£14.95 

Amazing 

£14.95 

Attack 

£14.95 

Bias to 

£11.95 

Blackjack & Poker 

£11.95 

Zero Zap 

£11.95 

Yah t zee 

£11,95 

Oldies But Goodies 1 

£11.95 

Oldies But Goodies 2 

£11.95 

Market Simulation 

£11.95 

Educational: 

Early Reading 

£29.95 


Music Maker 

£29,95 

Alligator Mix 

£24.95 

Alien Addition 

£24.95 

Demolition Division 

£24.95 

Dragon Mix 

£24.95 

Minus Mission 

£24.95 

Meteor Multiplication 

£24.95 

Touch Typing Tutor 

£24.95 

Addition Subtraction l 

£19.95 

Addition Subtraction 2 

£19.95 

Multiplication 

£19.95 

Division 

£19.95 

Numeration 1 

£19,95 

Numeration 2 

£19.95 

Early Learning Fun 

£14.95 

Beginning Grammar 

£14.95 

Number Magic 

£14.95 

Hangman 

£11.95 

Teach Yo 1 1 rs elf E x ten d eel 


BASIC 

£11.95 

Beginners BASIC Tutor 

£9.95 

Home Organisation: 


Personal Record Keeping £39.95 

Personal Report 


Generator 

£39.95 

Home Budget 

£24.95 

Home Financial 


Decisions 

£24.95 

Personal Financial Aids 

£11.95 

Other Applications: 


Inventory 

£85.95 

Invoicing 

£85.95 

Mailing List 

£85.95 

Tl Writer 


(Word Processing) 

'£85.95 

Mul tipi an (Spread 


Sheet Program) 

£85.95 

Statistics 

£54.95 

Terminal Emulator 

£49,95 

Ma rh s Routi ne Li brary 

£29.95 

Electrical Engineering 


Library 

£29.95 


Graphing Package 
Structural Engineering 

£29.95 

Library 

£29.95 

Programnting Aids 2 

£19.95 

Programming Aids 3 

£19.95 

Speech Editor 

£19.95 

Programming Aids 1 

£11.95 

Programming Languages: 

PASCAL Editor 

£99.95 

PASCAL Linker 

£79.95 

Extended BASIC 

£69.95 

TI Logo 

£69.95 

Editor/ Assembler 

£69.95 

Mini Memory 

£69.95 

PASCAL Compiler 

£59.95 

A-S.K. Applied Systems 
Knowledge: 

Hide and Seek 

t + b.a. 

Number Gul per 

r + b,a. 

Col 1 i ns-Educational : 

TI-99/4A Starter Pack 1 

£9.95 

T1-99/4A Starter Pack 2 
T 1-99/4 A Game Writer 

£9.95 

Puck 1 

T 1-99/4 A Game Writer 

£9.95 

Pack 2 

£9.95 

Chess Learner Pack 

£9.95 

Record Keeper Pack 

£9.95 

Ivan Berg Software: 

Maths Tester 1 

£9.95 

Maths Tester 2 

£9.95 

Physics Tester 

£9.95 

Chemistry Tester 

£9.95 

Biology Tester 

£9.95 

Human Biology' Tester 

£9.95 

Bond Associates: 

Easy calc 

£49.95 

Little Genius Ltd: 

Scrabble 

£29.95 


And is available at all these dealers? 

Carvel Is - Rugby 


Ail branches of: 

Argos. Comet, Dixons, 

Greens of Debenhatns, 

John Lewis, Rumbelows, 
Wigfalls. Zappo, 

Major branches of: 

Asda, Binns, Computers for All, 
CO-OP Currys, Fine Fare, Ketts, 
Phototnarket, Rymans, 
Spectrum, Telefusion. 

And at: 

ABC Computers -St Austell 
Akhrer - Harlow 
Anglia Audio - Bedford 
Anglia Sound - Stevenage 
Audio Marketing - London 
Audio Vision - Faversham 
B agnail - Stafford 


Combined Trading - Hatfield 
Computer Supermarket - 
Manchester 

Cotton TV - Peterborough 

Dean and Son - London 

Delta Electronics - London 

Densham Computers - Poole 

Desk Aids - Southampton 

Dodar- Ashton 

Fenwicks - Newcastle 

Galaxy Video - Maidstone 

H ami eys- London 

Harrods - London 

Heffers- Cambridge 

Hyman Computers - Manchester 

Landau -Sutton 

Lion House - London 


Micro Value - Amersham, Bucks, 
Midshires - Crewe 
Mil equip - Gloucester 
OEM Computers - Rugby 
Parco Electronics - Honiton 
REW- London 
Robox - Glasgow 
Science Studio - Oxford 
Sel fridges - London 
Star Trek Video - Wigan 
Toy and Hobby - Wigan 
Universal Warehouse- Reading 
V ideo Palace - London 
Vision Store - Kingston 
Welwyn Dept. Store - 
Welwyn 

And many other leading 
Computer Stores. 


Turn the page and see 
the unbeatable. 


PRACTICAL COMPUTING October 1983 


25 



The unbeatable 
TI Home Computer. 
It’s all the computers your 
family will ever need. 


Buying a home computer is something 
you have to get right first time. It’s too 
late when you’ve got one to find it 
won’t take plug-in software. Or can’t 
be programmed without an expensive 
accessory. 

The TI Home Computer is a 
real computer system 

Tine TI Home Computer has got the 
memory power you might expect 
from more expensive computers, built 
in. At its heart isapowerfi.il TMS 9900 
16-BIT Microprocessor Most other 
home computers have only an 8-BIT. 
And you can expand the memory 
from 16K of RAM up to 52K. 

The total memory capacity is 
114K Bytes. 

A wide range of 
software for everyone 

Another feature that makes the TI 
system so powerful, yet so easy to use 
is Solid State Software.™ These plug- 
in cartridges cover everything from 
space games like Parsec™ to teaching 
maths, managing home finances and 
composing music. And the range is 
getting wider all the time. 

It even has what 
professionals look for in 
a home computer 

CPU: TMS 9900 16-B1T, plus 256-byte 
Scratchpad RAM. 

Memory: Total U4K byres; 26K bytes 
ROM internal; up to 36K ROM cartridges 
external; 16K built-in RAM expandable to 
52K bytes. 

Keyboard: 48 Key QWERTY, alpha lock, 
function key auto repeat. 

Sound: 5 octaves, 3 simultaneous tones, 
noise tone. 

Colour: 16 foreground and background. 
High resolution. 

Interfaces: Cassette, TV, 2 joysticks, 
main peripheral port. 

™trad£rrfcirk of Texas Instruments. 


More than one 

programming language 

The standard programming language, 
TI BASIC, is built into your TI 
Home Computer so you can begin 
programming right away. But there’s 
an expanded range of optional 
languages like Extended BASIC, TI 
Logo, USCD-Pascal, TI FORTH and 
Assembler. 

With these you can fully expand 
your programming skills. 

A wide range of peripherals 

Most computers lose a lot of memory 
when you add peripherals. The TI 
Home Computer is different. Every' 
peripheral comes with its own built-in 
programs to keep the loss of memory 
to a minimu m. 

The convenient Peripheral 
Expansion System houses up to eight 
peripherals. Additional hardware 
cards simply plug in. You can even add 
a complete Floppy Disk Memory' 
System. 

The peripherals include memory 
expansion, RS232 Interface, P-Code 
card and more. There’s also a 
sophisticated matrix printer and Solid 
State Speech™ synthesizer -which 
you can use with your own TI BASIC 
programs. 

A lot more for no more 

TheTI Home Computer gives you so 
much more without costing more. 

At today’s price it’s exceptional 
value. Take your family round 
to try one. If you never try 
it you’ll never know what 
you’re missing. 

. Texas 
Instruments 

Creating useful products 
and services for you. 



• Circle No. 116 




NETWORK 






* The Network will support over 30 terminals * Message facility 

* 1 1 * 8 Megabytes Hard Disk Storage * Shared or local printer 

* Global drive with common read only files * Terminals can support local floppies 

* Password protected, read/write files * Fully intelligent terminals with dual processors 

* Common read/write files with file locking & 64K System RAM 


Limited number of Dealerships 
available in the U.K. 


QUANTUM COMPUTER SYSTEMS LIMITED. THE LEEDS COMPUTER CENTRE 
55, WADE LANE, MERRION CENTRE, LEEDS LS2 8NJ 
Telephone (0532) 458877 



• Circle No. 117 


Random access 


"At last in its proper setting, the infinite 
has assumed a respectable place next to 
the finite, just as real and just as 
dependable, even though wholly 

different in character . Whatever the 
infinite may be, it is no longer a purple 
cow , ** 

Edward Kasner and James Newman 
Mathematics and the Imagination , 1940 

in gOdel's arithmetisation of 
mathematics, the key concept is that of the 
Gddel number. Hilbert, in 1904, had 
noted that symbolic logic could be treated 
as though it were a branch of elementary 
number. But it was Godel, in 1931, w ho 
worked what this actually implied in 
practice. The method was directed 
towards Russell and Whitehead's 
Principle Mathematical and an English 
translation of his original German title 
might be “on formally undecidable 
sentences of principia maihematica and 
related systems.” 

Godel starts with a set of basic axioms 
of number theory which effectively 
correspond to three of Peano’s axioms of 
number: 

• the successor of any number cannot be 
zero; 

• if the successors of two numbers are 
equal, then the two numbers are also 
equal; 

• and if a certain property is true for the 
number zero, and if true for any number it 
is true for its successor, then the property 
is true for all numbers. The latter is the 
axiom of mathematical induction. 

In GbdePs logical symbolism, the 
number zero is shown as 0, the number 
one is shown by fO, the successor of 0, two 
is shown by ffO, and so on. There is only 
one primitive number in his system and 
that is 0, all other numbers are the results 
of operations on that number using the 
primitive f. Other primitives are simple 
variables, for example, X in his first axiom 
~ {f X = 0) 

it is not true that the successor of any 
number is zero. These primitives are used 
to create secondaries, more complex 
arrangements which on analysis end up 
being assertions about numbers or 
variables. 

At a different level there are secondaries 
which involve propositional expressions, 
or expressions which can be turned into 
such, and assertions about the relationship 
between the elements implicated. For 
example, in his second axiom 
fX = fY -*X = Y 

if the successor of X is equal to the successor 
of Y, then X is equal to Y, Either 
side of the implication is ultimately 
composed of primitives but the 
implication is of a different order of 
things. 

In the 1931 article Godel starts his 
arithmetisation by associating each of the 
primitive signs in his symbolism with a 
natural number. 


Symbolic 

logic 

Boris Allan continues his analysis of Godel’s work in 
relation to threaded interpretive languages. 


Symbolism 

0 

1 

and natural 

f 

3 

numbers. 


5 


V 

7 


P 

11 


( 

13 


) 

17 


X 

19 


Y 

23 


and so forth — any scheme of assignment 
which uses the prime numbers would 
obviously do. The Godel numbers for 
these primitives correspond to the 
addresses of the locations Tor primitives in 
threaded interpret ive languages. If you 
show a properly of X, that is a higher 
order type, by X2 then this is given the 
Godel number 19 2. A property of a 
property of X is X3, with a Godel number 
19* 3, and so on until infinity. 

A secondary in a TIL or threaded 
interpretive language also has an address, 
that is, a number, and that number when 
used points to an unambiguous set of 
further addresses, which are either the 
addresses of primitives or further 
secondaries. The Godel numbers of 
primitives are associated in a special way 
to enable the content of any formula to be 
established from the GOdel number of the 
formula. 

The third of GbdePs axioms is 

X2(0)X P(X2(X))-*X2(fX))^X P(X2(X)) 
that is, if there exists a property of X which 
is true for 0, and if, for all X, when true for 
X it is true for the successor of X, then the 
property is true for all X. Note 
that mathematical induction cannot be 
expressed in a single axiom without use of 
a variable of a higher type that is X2. 

The implication — ► is not one of 
Godel’s set of primitive symbols, but as A 
— ► B is the same as ~ A v B, part of the 
above can be re-written 

X P(-X2(X) v X2(fX)> 

which has the Godel number 

2" 19 # 3* 11 * 5 ‘ 13 * 7 " 5 * 11 ‘ 19 2 * 

... * 47" 17 

This number, though large, can be 
unambiguously factorised into its 
constituent elements so that you can 


always reproduce the formula. If the 
numbers of formulae in a proof, a proof is 
no more than a sequence of logical 
formulae, are FI, F2, F3, ... Fn, then the 
Godel number for the proof is 
2 FI *3 F2*4 F3*5‘ F4*. . . 
and this method associates one and only 
one number with each formula or 
sequence of formulae. Thjis is the 
arithmetisation of mathematics — a 
bootstrapping exercise. 

The threading through addresses which 
characterises TlLs has a very dose 
analogue here. You have a Godel number 
which is factorised at the first level; you 
have a TIL word which produces a series 
of addresses; some or all of the numbers 
which arise from the faciorisation have 
then to be factorised to produce further 
numbers; some of the addresses lead to 
sets of further addresses. The process 
continues, on both accounts, until you 
reach the system primitives. 

The transfinite numbers are shown by 
the Hebrew for A, aleph, but to save 
typographical contortions l will simply use 
A — though still calling it aleph, A few 
characteristics of the first transfinite 
number aleph-null, A(0): 

A(0) = A(0) + 1 
A(0) = A(0) + A(0) 

A(0) = A(0) * A(G) 

though 

A(1> = A(Q) A(0) 

where A(l) is the next transfinite number, 
aleph -one. If these strange equalities are 
studied, it is obvious that they contradict 
Peano’s axioms, for one property of zero 
is that it is different from its successor. So 
is it always possible to unambiguously 
factorise a GOdd number, is there some 
point at which the number is “too large”? 

Return to the TIL. There comes a point 
at which the physical confines of the 
computer memory mean that we cannot 
extend the words in the memory any 
further. A TIL is manageable, it respects 
finity and it also asks for the mechanism 
by which an operation is to be performed. 

A word may, for example, refer to itself — 
a TIL asks what that self-reference means 
in practice. 

Any secondary in GodeLs scheme will 
( continued on page 38) 

29 

• Circle No. 117 ► 


PRACTICAL COMPUTING October 1983 



Why all other spreat 


In the early days of micros, the first 
spreadsheets appeared, using complicated cell 
co-ordinate references to define plans. 

This made the most of limited com- 
puting power but plans were tricky to write, 
and difficult to read later. 

Today’s micros are much more sophisti- 
cated but all the spreadsheets are more or less 
the same as they always were. All that is, 
except PlannerCalc and MasterPlanner, 
Described in a recent university report as 
“ . . the best spreadsheet package currently on 
the Market” PlannerCalc and MasterPlanner 
are true business aids. 

Dyed in the wool calc freaks won’t like 
them but businessmen will. 



piAMNBlGf 

BusiSflanningoni 


immediately see their effect on every 
thing else in the model. 

It comes with 
the best manual 
on the market and 
it’s suitable for 
most micros with 
a™CP/M2.2 
operating system, 

64K of memory, 
giving at least 900 
cells, minimum 
screen width of 80 
characters and 2 
floppy disc drives. 

MUCH MORE POWER, 
NOT MUCH MORE MONEY 


BT.SS 




NEW USERS START HERE 

PlannerCalc at ,£85. 00* is now accepted 
as the first choice for people new to financial 
planning. 

Designed for 8-bit micros, it boasts the 
kind of features that you’d expect to pay twice 
as much for. (Buy PlanneiCalc’s nearest rival 
and you’ll have to.) 

Unlike all other‘calc’products 
it allows you to enter calculations 
in a language you understand. 

Plain English. 


For example: 

LINE 1 SALES=100. 150. 175.210 

LINE 2 EXPENSES=GROW 70 BY 1 5% FOR 4 

LINE 3 NET=SALES- EXPENSES 

LINE 4 CSALES=CUM SALES 

COLUMN 5 YEAR=SUM OF COL I THRU COL 4 

So it’s much easier to use. 


It uses the popular “spread- 
sheet” approach with a window 
that can be rolled in all directions. 

Which means you can enter 
new figures and rules and 


'ScrtKt'i 


MfWiJ! iulf 1 Hi 


s. 


toft J 


lifiT-rtm Ch*iwIh 
I filnm LU 


MasterPlanner is the most powerful 
spreadsheet system currently available wit 
its increased matrix size, 2000-3000 cells o 
most 64K micros. (But at £245* it certain! 
isn’t the most expensive.) 

Consolidation of models, allows you t 
create separate plans for each department an 
then combine them into an overall compan 


COMSHARE DEALERS 


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30 


PRACTICAL COMPUTING October 1983 


sheets are out of date. 



plan. Data transfer to word 
processing and other systems 
lets you incorporate figures in 
reports and output to a data 
base. It also has extensive 
formatting facilities which 
means you can produce reports 
that wouldn’t lookout of place in 
the board room. 

It can store up to 25 stan- 
dard reports to run when you need them. It’s 
got full WHAT IF? analysis and direct 
editing of both spreadsheet and logic display. 

JUST AS EASY TO USE 

All this increased power doesn’t mean 
you’ll need a degree in advanced computing 
to understand MasterPlanner. 

It works on exactly the same 
system as PlannerCalc and models 
written on PlannerCalc run without 
modification on MasterPlanner. 


OVER 10 YEARS EXPERIENCE 

When you invest in MasterPlanner or 
PlannerCalc you’re not just getting the best 
software money can buy. 



flfc* 


m 



16 BIT VERSION 

A new version of Master- 
Planner has been specifically designed 
for the 16 bit micros like the Sirius 1 
under ™CP/M-86 or the IBM personal using 
either CP/M-86 or ™MS DOS 1.1. With a vast 
matrix size of over 7000 cells on 128K and 
even more with larger memory, you’ll at last 
be able to make the most of your micro. 

ULTIMATE POWER 

Fastplan is the top Comshare micro 
planning system. 

It’s file- based, allowing development of 
large scale models; with a staggering 18,000 
cell matrix; full financial functions plus back- 
wards iteration, file input and output; and 
much more. Yet, because it can be menu 
driven it is easy to use. For the full story, tick 
the Fastplan box when you return the coupon. 


) You’re also getting the kind of back up 
and after-sales service that only a company 
of Comshare’s track- record can guarantee. 

If you’d like to know more about any 
product, call in at your local dealer or fill in the 
coupon and send it to us. 


* Plus VAT and jK>&t & package. 


Making the computer make sense. 

*CP/M and ^CP/M-86 are the registered trade marks of Digital Research Inc. 
Comshare Lid .,32-34 Great Peter Street, London SW I P 2D B. Telephone: Ul 222 5665, 

rz : Department lit PC. CuuiHliare Ltd.. 324*4 tit. Peter Street. Undtm ,$W I P 2I)B 1 

Pluaite send itw? 


Q«y 

Product 

Micro 

Op System 

Disc Size 

K 

Arrmu 

mi 

P' 


PlannerCalc 

@ £99.50 
(H bit only) 


CP/M 2.2 

HVSW' 





MasterPlanner 


CP/M 2,2 

H V5W 





MasterPlanner 

i m PC 

MS DOS U 

avsw 





MasterPlanner 


CP/M-86 

87.W 




All prices inel ude VAT and postage & pac king TOTAL 



Please send me informa (ton about Fastplan 


I enclose a cheque/ postal order for 

Please debit my Access Card No, 

Bardaycard No 

Signature . 

Name 

Address 


_made payable to Comshare Ltd. 

for T. 

for £ . 


_TeL No._ 


| Pi case allow 28 days for del i vety. VA T No .2384l86 4fl, Regi stered No.<MQ4()6. ] 

Cam* hate, men* tlw rif hi my outer* Any » eeqil ant .t wlU b* j-ubp* l i* n-nna and e oitdiUwn 

• Circle No. 118 


PRACTICAL COMPUTING October 1983 


31 



Shopping fora Micro 

BUYANCOpphz 


The Personal 
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APPLE lie 


Apple lie 
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with controller 
80 Col Card 


Apple lie 
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Quickfile 
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Microsoft CP/M 


£899 


£645 
£1 10 
£299 

£200 
£150 
£119 
£ 60 
£175 
£200 


The Business 
Solution 


APPLE 

in 

Apple III 256K . 

Monitor 111 1 

SOS System Software > 
with Apple 11 emulation j 
built in disk drive } 

£1999 

Apple HE 256K ) 

Computer as above ( 
plus Profile 5 mbyte | 
hard disk ) 

£2800 

Applewriter ill 

Visicalc III 

Quickfile III 

(All 3 packages for £295) 

£130 
£170 
£ 55 

Complete range of invoicing, ledgers 
and stock packages available. 


The 

Revolution 


Attend one of our seminars and 
let us introduce you to 
Apple's™ revolutionary new 
personal computer for the 
office. Please telephone or write 
for details, 

PRINTERS 


EPSON 


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FX80 £375 
RX80 £265 
MX 1 00 £399 


82A 

92 


£299 

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THE SUPPORT PACKAGE 

Training — free half day course to take you from an appreciation of 
the Apple computers to an understanding of 
applications packages. Specialist courses are also 
available. 

Installation — on your premises for a small extra fee. 

Ongoing Support — handholding on both software and hardware. 

One full year's guarantee on all parts and labour. 

On site maintenance contract available. 

Comprehensive range of software, supplies, listing paper, 

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ALL PRICES ARE EXCLUSIVE OF VAT 


For computerised solutions to business problems contact 

SIMMONS MAGEE COMPUTERS LTD 

13 YORK STREET, TWICKENHAM, MIDDLESEX TW1 3JZ 

01 - 891-4477 


32 


PRACTICAL COMPUTING October 1983 

• Circle No. 119 


■eestez pub 

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/aoud uj pjbpub;s aq; 6umas s; ja;uud xu;buj 08 LLW aqi 








"You are a QX-10 answering questions on all 
accounts including payroll, bought ledger, 
stock control; word processing..." 



With over 20 years of experience in 
producing high quality printers, Epson have 
now masterminded a fully integrated desktop 
microcomputer that will more than earn its 
keep within your business. 

The QX-1Q is capable of performing all 
the tasks you will ever require of it, quickly 
and efficiently. Installation of the QX-10 can 
be carried out with the minimum of inter- 
ruption, and with its easily understandable 


keyboard, it is simplicity itself to operate. 
Having such a diverse range of software 
packages available such as database from 



i i 

I □ I would like a demonstration of the QX-10. 


Pearl and office productivity and accountancy Extraordinary product, 
from Peachtree with C P/M and multifont Exeeotional an til it v 

BASIC as standard, the QX-10 can supply all * H 


□ Please ask my Epson dealer to contact me. 
Name _ 


the answers whatever your business, Epson (UK) Limited, Freepost, 

t . . 11 . i . i ^ it i . Wembley, Middlesex HA9 GBR. 

Just look at What sonoher.a big memory Sales En y uiries: Fleefone 2730 

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resolution graphics at that. 

The ability to communicate easily with 
other machines, including our own HX-20 and 




PC 10/10 j 


• Circle No. 244 




So cheap to 
keep in touch 


the computing power now available to the 
individual user via the new generation of 
16-bit microprocessor-based personal 
computers is quite phenomenal. In many 
respects it exceeds the capabilities offered 
by those big expensive mainframe systems, 
which were once the mainstay of the 
computer industry. But despite their 
obvious power, most personal computers 
still lack one of the most useful features of 
the mainframes: easy communication with 
other users and the ability to share a 
common database. 

However, judging by the latest batch of 
microprocessor peripheral devices this is a 
drawback which will soon disappear. 
Before long it will be the exception rather 
than the rule for personal computers to 
operate in splendid isolation in a dark 
corner of the office or living room. 

Many multi-user systems particularly, 
need to communicate over long distances 
by the public telephone system. This need is 
currently satisfied by Modem — 
modulator/demodulator — units, which 
can be used to convert the serial RS-232 line 
of a terminal or VDU to the voice band 
signals expected by the telephone network. 
Trouble is these Modems are quite complex 
as they have to convert the logic-level 
signals from a terminal into audio 
frequency tones before transmission; they 
do the reverse at the receive end. They must 
also cope with the distortions inherent in 
long distance connections and the many 
other peculiarities of the telephone link, 
which may include land lines, microwave 
links and even a satellite between the 
transmit and receive terminals. Complexity 
equals expense and so this form of 
communication has in the past been largely 
ruled out for low-cost personal-computer 
applications. 

But the semiconductor chip manu- 
facturers have not been neglecting this 
problem. Now that the personal- computer 
revolution is well underway advances in 
chip technology and the attractions of a 
huge potential market have spurred the 
development of self contained Modem 
devices. These can be built into every 
micro mpu ter at very low cost to provide a 

I direct telephone connection to even the 
most humble office system. 

The integration of a complete Modem 
system onto a single silicon chip is by no 


means a trivial matter. Traditional 
Modems are essentially analogue — rather 
than digital — systems, and rely heavily on 
the use of sine-wave oscillators and 
inductor filter circuits for correct 
operation. To satisfy the single-chip 
requirement an analogue signal is simulated 
using digital techniques, with the result that 
the new generation of Modems are really 
high-speed dedicated microprocessor 
systems, internally as complex as the 16-bit 
general purpose microprocessors they will 
support. 

Several of the major chip manufacturers 
have recently announced sophisticated 


by Ray Coles 

single-chip modems, which will ensure that 
competition is fierce and prices low; the 
one which caught my eye was the 
AM-79 TO from Advanced Micro Devices. 

AMD has brought the traditional 
advantages Of VLSI digital circuitry to bear 
on the problem and has made its device 
totally programmable in order to suit the 
various standard communication protocols 
in use in the U.S. and Europe. Analogue- 
signal generation and processing is 
simulated by using a high-speed digital- 
signal processor, which has its own 24K 
ROM, 1.3K RAM array, digital- to- 
analogue and analogue-to-digital 
converters fabricated on the same chip. 

The entire system lives in a tiny 28-pin 
dual-in-line package and runs from dual 5 V 
supply rails using just 600mW of power. 
Voice band Frequency Shift Keying, FSK, 
data rates of 300, 600 and 1200 baud can be 
selected, as can one of the nine Bell and 
CCITT recommended communications 
protocols. 

With this sort of capability now available 
for a few pounds, we can expect all future 
microcomputer systems to have long 
distance communication facilities available 
as a standard feature. This would allow 
even a basic office micro to keep in close 
touch with all that lovely data available in 
the outside world. 

Modem links are good for long distance 
access to a central data base or larger 
computer, but due to the limited frequency 
response of the standard telephone network 
data rates are restricted, making the 
transfer of large quantities of data a tedious 


business. Over shorter distances data 
transfer rates can be increased dramatically 
by avoiding the restrictions of the telephone 
system; using instead dedicated high-speed 
communicaitons links called Local Area 
Networks, LANs, 

Using a LAN, such as Ethernet, data 
transfer rates of 10 million bits per second 
are possible. This means all the 
microcomputers in, say, an office block can 
be linked together for the interchange of 
messages and the sharing of precious 
resources like hard-disc systems and line 
printers. 

Unfortunately LAN controllers are 
complex and therefore expensive. But the 
semiconductor manufacturers are falling 
over themselves to provide cheap VLSI 
solutions, and a whole flood of new devices 
are about to be launched into an eager 
market. 

Ethernet controllers are a good deal 
more complex than the simpler Modems, 
but their complexity is more easily handled 
using digital techniques. Again the new 
generation of single-chip controllers will 
depend heavily on the use of dedicated 
microprocessors to provide the clever bits. 

Take the Intel 82586 LAN controller: 
when used with the companion 82501 
driver chip, required to drive the coaxial 
cable used for interconnection, the device 
will implement the full Ethernet 
specification as defined by the original 
sponsors of the standard, the DEC, Xerox 
and Intel grouping. In the past about 80 
integrated circuits have been required for 
the job, but with the advent of the 82586 a 
single 48-pin package is all that is needed. 

The new Intel device takes the burden of 
link control away from the associated 
microprocessor. It merely requires it to 
assemble a message for transmission in its 
own memory space, or to retrieve received 
messages placed back in the microprocessor 
memory space by the controller. The 82586 
has a built in DMA controller which allows 
it to take control of the system bus for the 
retrieval and replacement of messages, only 
interrupting the busy CPU when all the 
hard work has been completed. 

Eventually we can expect LAN controller 
chips like the 82586 to cost less than £20 
each, making the provision of this form of 
communication a logical option for future 
16-bit machines. Q 


PRACTICAL COMPUTING October 1983 


35 



BRITAMS 
NoL 
BORNE 
DEALER! 





THE NEW OSBORNE EXEOJTWE 


Designed to appeal primarily to the corporate business 
user the Executive offers some exciting Osborne features. 

• New T amber display screen 

• Terminal Emulation - allows you to connect straight into 
the company computer system 

• 6 Software programs inclusive in the purchase price 

• *COMM- PAG T M option - giving you instant telephone 
connection 

• Complete portability - vital to working flexibility 

• Increased speed and capacity - 1 28 K user memory 
BOOK bytes to each disk drive. 

' Suhtecc eo B 1 1 risb Telecom .a pprova l f> 

TheNew Executive includes | I 

six Software'programs to the | Mfisd f 

value of £1200! Make an 

appointment now for a / \ 

demonstration of the - - \ 

Executive's unique and . 

positive benefits All inclusive price £1995 + VA m 

I COMPUTE R 

Southampton House, 192-206 York Road, 


When you buy an Osborne at 0 1 Computers you also 
benefit from the kind of back up you would expect from 
Britain's No. 1 Osborne Dealer 

* User training for you and your staff. 

* Easily arranged credit terms. 

* Sophisticated technical and service 
backup. 

We would welcome a visit from you, to our showrooms 
where we can offer you coffee, an informal atmosphere and 
of course a personal demonstration of the incredible 
OSBORNE 1 and the superb New EXECUTIVE. 


Call us for an appointment 
sales/mail order, or simply 
drop in! 

01-228 2207 

% N. B. We are open until 
8.30 pm weekdays and 
10am - 1pm Sat 

r 

i 
i 
i 
i 
i 

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Please send me a copy of 
your introductory brochure and 
details of the Osborne Executive 



Name . 


Address _ 


.Tel No, 


Occupation. 


Southampton House, 192-206 York Road, London SWH 3SA 


• Circle No. 135 


36 


PRACTICAL COMPUTING October 1983 







The market 
leaders!... 


ATA’S philosophy is to 
ensure that our 
customers have quality 
computer hardware and 
software products at 
COMPETITIVE prices, 
together with technical 
assistance required to 
efficiently operate their 
computer system. 

Export specialists - ring or telex for details 

...with recognised professional support 

System Utilities £ Kayproll £ 

Diagnostic package ,,, 69,00 Fraah from the US, A, I The best value portable micro 

CP/M configuration package ....... 1 1 9.00 from KAYPRO . . . including Software 

M S DOS prog rammer* tn n Ik it 169.00 

Sirius 1 hardware reference manual 45.00 KAYPRO II 2 x 2 00 K disc drives 169S.UO 

IEEE 468 package 1 69.00 KAYPRO IV 2 x 40OK disc drives £ 1 9 50.00 

Graphics toolkit 1 69.00 KAYPRO X 1 x 400K disc drive and built in 1 0MB 

A synchronous com munlca Irons 169-00 Wi nchester 

remote batch „ 265-00 Other software including financial ledgers etc slap 

3270 emulator 340.00 aveileble. 

i.C.E. Winchester Subsystems Hyperion 



Sirius Hardware £ 

Sirius t 128K 1.2mb disk drives 1796.00 

Sirius 1 256K 2.4Mb disk drives 2395.00 

Sirius 1 256K 1.2mb disk drive 

S, 10Mb 3295.00 

internal Winchester 

128K RAM Boards 264,00 

256K RAM Boards 399.00 

334 RAM Boards 499.00 

51 2K RAM Boards 575,00 


ZBG CP/M 80 System 


5 Megabyte 1395.00 

10 Megabyte 1599,00 

20 Megabyte 2099,00 

40 Megabyte 3399-00 

Tape Streamer 

Wi II fit all drives as above £ 1 6 6 0, 00 

and also Apple Profile 5Mb 
(Please state which drive 
when ordering) 

Cartridges DC 30QA (6Mb & 1 9Mb) 1 6.00 

DC 600A (20Mb) 25.00 


I Size after Formatting. One year's on-site 
maintenance.) 

MULTIPLEXOR AVAILABLE FROM E699.00 

Colour Monitors 


Luxor high resolution 

2 5Mhz linear & TTL 499,00 

Ksge Denshl medium resolution TTL 325.00 

Kega Denshi low resolution 265.00 


We also stock the Hantarex RGB monitors, as 
recommended by Apple in Europe. 


Hyperion 256 x 2 MSDQC, Basic 2950.00 

Printers & Plotters 
Epson 

Epson RXOO 1 20 CPS 260,00 

Epson FX8Q 1 60 CPS 350.00 

Epson MX 100 100 CPS 420.00 

Apple 

APPLE Dot Matrix 1 20 CPS 349.00 

APPLE Letter Quality Printer 1 199.00 

Ricoh 

Ricoh 1300 Flowriter 1099,00 

RichoRPI 600 Flowriter 1499,00 

Mannesmann Tally MiTI 60L 550,00 

Mannesman Tally MT1BQL 690.00 

Plus full Range of Centronics Printers Available 

Plotters 

Hewlett Packard HP7470 1066-00 

He wl ett Pa oka rd HP7 4 7 5 1 A 31 T BA 

Calccmp 8 PEN [A3) .. 2999,00 


SS£ 280 CP/M BO system 395.00 

Sirius Software 
Languages 

C Basic 36 .... 179.00 

Level 2 Cobol with forms 2 595,00 

Microsoft Basic compiler 269-00 

Microsoft Pascal compiler 335,00 

Microsoft Fortran compiler 335.00 

Word Processing 

WordStar 269.00 

Spell Star 120.00 

Marl Merge 120.00 

Word Mailer .60.00 

Databases 

dBase II 365,00 

Autocode 180,00 

DataStar 135.00 


WE ALSO STOCK APPLE W AND HEWLETT PACKARD 


TERMS AND CONDITIONS 

For delivery please add 
£G-£1 99 + £5, £2GG-£1 499 + £13 H 
£1500 + 1'/!%. 


CHEQUES WITH ORDERS 

Please allow 1 0 days for clearance. 
PLC r s r public sector etc 30 days 
credit available on official orders, 
subject to 5% shtsess 

credit charge. , 


ATA — LONDON 4 Albion Hse, 
1 Back Hill, London EC1.01-833 



Telex 251 02 CHACO MG 


Spreadsheet 

Multiplan 180.00 

CaEcStar BO. 00 


PRICES EXCLUSIVE OF VAT AND CURRENT AT TIME OF 
PRINTING 



ATA — ST ALBANS 70 Park Street, _ 
St Albans, 072774361 
ATA - SHEFFIELD 72 Eldon Street, 
Sheffield, SI 4GT. (0742) 700802 

FREEPOST SHEFFIELD SI 1AY 


PRACTICAL COMPUTING October 1983 


* Circle No. 121 

37 




Random access 


Symbolic 

Logic 

(continued from page 29) 
be shown as Sec? where the ? is replaced by 
an indentifier — compare my earlier 
analysis of secondaries for TILs, Each 
secondary, say a formula, will be given a 
Godel number Number. Sec?, and to find 
what the number means, that is, to unravel 
the formula, you have to factorise that 
number. To factorise the Number.Sec? to 
find what is the formula you 

NUMBER.SEC? EXECUTE 
in direct analogy to a TIL. 

Take a secondary SecX, and suppose 
this is composed of a series of other 
secondaries, taken in order, SecA, SecB, 
and SecC 

: SECXSECA SECB SECC ; 
or 

; SECX NUMBER. SECA EXECUTE 
NUMBER, SECB EXECUTE 
NUMBER, SECC EXECUTE ; 
where Number. SecX is the Godel number 
of SecX, and likevvise for the others. How 
is it possible to incorporate variables? A 
variable is effectively a dummy which can 
be replaced by any value; it is an 
lnpumumber, in terms of my earlier 
analysis of TILs. You will assume that 


Inputnumber, 1 is the first variable, and it 
may appear more than once in a 
definition, and the same for 
lnputnumber,2, etc* 

The-operation ?Provable when applied 
to a number gives the result true if the 
sequence of formulae are a valid proof 
within the system, false otherwise. That is 
NUMBER. SECX 7PROVABLE 
and now you can produce Coders famous 
result. 

Let SecY be the main secondary in 
which you are interested, let SecX 
comprise the main body of the sequence of 
formulae, and let there be a variable 
inputnumber, which corresponds to X in 
the arithmetic 

: SECY SECX INPUTNUMBER EXECUTE ; 
As you saw in the first part, Inputnumber 
can be replaced by Number.SecY, and so 
SecY can be re-written as 
: SECY SECX NUMBER. SECY EXECUTE ; 
— one form of recursion. 

Godel designs a special formula, SecG, 
first he makes the simple formula 
; SECG INPUTNUMBER 
? PROVABLE NOT 1 

which asserts that the formula whose 
number is to be supplied, via 
Inputnumber, cannot be proven. The 
number for this formula is Number. SecG, 
and what Godel does is substitute for 
Inputnumber: 

: SECG NUMBER.SECG 
? PROVABLE NOT ; 

and my earlier worries about the meaning 


of recursion, in part 1 in the September 
issue, are reinforced. 

Consider how a TIL might analyse this 
formula/definition* It would not come to 
any conclusion, the process would never 
end until memory ran out. Godel assumes, 
along with many other mathematicians, 
that in mathematics the story need never 
end, it could carry on until infinity. 
However, as noted earlier, this is not to 
say that at some non-Peano transfinity the 
solution would not be resolved. People 
can resolve it. 

Computers are not generally used to 
play meaningless games, apart from in 
some reaches of A I and computer science 
“ long may it continue* TILs were 
developed to provide a powerful method 
of using computers. Interestingly, it seems 
as if the TIL philosophy is a practical 
application of metamathematics, the 
arithmetisation of mathematics. 

It is generally acknowledged that 
Gddel’s method is the most powerful 
method yet devised for studying 
mathematics and logic, and this 
corresponds to the power of TILs. GodePs 
method does have its problems, the 
unprovability formula, but these are only 
the problems inherent in the extension to 
ihe infinite of finite ideas. 

A TIL is an artificial intelligence 
language which accepts that there is no 
infinity but has not — as far as I know — 
been accepted by the AT community which 
still believes in the infinite* Q 


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38 


• Circle No. 122 


• Circle No. 123 

PRACTICAL COMPUTING October 1983 



If your computer 
gets stuck in a dead-end job 
you clearly haven't got dBase II. 




Acctg, j Payroll j Inventory 


Programs 


Employee 


There you are with all that 
microchip potential and no 
software that's 
man enough 
to exploit it. 

Too 

specialised, 
too basic, too 
difficult, too risky. 

Over the top in everything except 
flexibility! And that's a downright 
insult to intelligence - yours and the 
computer’s. 

For years now, the computer 
industry has been hooked on data- 
bases. And there's absolutely no 
doubt that an effectively run database 
is the only certain route to successful 
information management. The micro's 
got the horsepower, so 
why shouldn't you 
have the software to 
go with it? 

No reason at all. 

That's why ASHTON 
tate developed 


INFORMATION 


dBASE 


£ 


£ 


f 


£ 


Acctg 


Customer 
_ Data 


Sales 

Data 


Other 

Data 


DATABASE 


absolute safety. 

These features and more have made 
dBASE II a 
standard for 
microcomputer 
information 
management. And 
it's a standard that's 
as good for the one- 
man business as it is for the larger 
company. 

But don't just take our word for it. 
Ask any dBASE II dealer and try it out 
for yourself for 30 days. 

You're hardly taking a risk, because 
if you don't like it, you'll get your 
money back! But before the 30 days is 
up you'll wonder how you ever managed 
without dBASE II. 

So do your computer 
a favour. Give it a copy 
of dBASF 
For 

nearest dealer contact 
ashton-tate distributors: 


dBASE II. 


ACT (Pulsar] 021-454 8585 


With dBASE II you can harness all your 
microcomputer's potential. It gives you a 
flexible structure on which to build business 
information and a straightforward means to 
develop complex and varied applications. In 
short, dBASE II gives you all you need to 
manage and use information. 

When your business grows, you can change 
the way you handle information without 
changing the information itself. You can 
develop your own applications or buy them in 
ready-made. You can even build a set of menu- 
driven routines and let untrained people loose 
amongst your most valuable information in 


Arbel Ltd. 1 0603) 3938 1 

Encotel Systems 01-680 6040 

Ferrari Software 0 1-75 1 579 i 
Midlectron (Belpeij 681 1 

Pete & Pam (07061 227011 

Soft Option (0476) 860171 

Software Ltd. 01-833 1173/6 

Tamsys [Windsor) 56747 
Tradesoft 01-627 1800 

Xitan Systems (0703) 33471 1 

Supported by: Ashton-Tate (UK) Limited, 
Cofferidge Close, Stony Stratford, MK11 1BY. 

dBase II is one of the quality range of products which include The Financial 
Planner, Strategist and Friday, all registered trademarks of AshtonTate. 


ASHTON -TOE ■ 

• Circle No. 125 

39 


PRACTICAL COMPUTING October 1983 


G.W. COMPUTERS LTD LONDON’S WEST END NATIONWIDE OVERNITE SERVICE MORE PRODUCT 

RANGES BETTER SERVICE PROBABLY THE WIDEST SELECTION OF NETWORKS... 

MICROS... AND PRINTERS ON DISPLAY NATIONWIDE 


‘THE NEW DBMS 


I (series III of the world’s first ‘task-robot-programs’) 
““‘FEATURES* 

1400 character record sizes..... 32000 records per filename. 


it * * * * * 


mathematical scratchpad 20 malh/200 sub fields per record 

record relational Indexes field and record related formulae 

translateable to any language............. l Jump-to' any of 32000 records per file.... 

U ser-def ineable report Ing M random/ binary/Xey/mu ft I pie field searc h . . 

field protect I onf classification 'If-then 1 questioning....... ♦. 

eithar-or. same as. greater, smaller....... file protecttonfpas sword entry 

sorts 'aipha or numeric 1 any window., >, range match, not mate h i nteger m atch 

12 online file architectures sort speed 500 records per 20 seconds.... 


12 online file architectures 

240 fields using cross-referencing 

cross-rec ord caicu 1st I ons 

■Jump-io' any record in 12 files 

User definable files.'fleld words/sizes.. 

endless 'elther-or' matching 

formulatefrecall on selection criteria 

13 interrogation question types.. 

short filing oulput/audit trails. 

Word -star & Mbaslc compatible.. .... 


DBMS 1 1 1.7 NEW SWITCH MODE FACILITY ENABLES YOU TO CROSS UP TO 12 DIFFERENT FILES 
(32000 RECORDS PER FILE) PRE-SELECTING ANY OF UP TO 20 FIELDS PER RECORD/FILE FOR 
DISPLAY/PRINT OUTPUT (240 FIELDS) IN ALL ONE MASSIVE ENQUIRY CAN PASS THROUGH 

384,000 RECORDS 

You might have two files whose records are directly related to each other, so that the first file (say containing names and addresses! refers 
to the second file fsay financial and other information relating to the same record numbers in the first file) directly. Then you can simply 
select that in file 1 you are interested in just the name and telephone numbers, whereas in file 2, you are interested in the income, trading 
period and number of branches, information. Your enquiry can then passthrough both files highlighting that information only. Actually there 
doesn't need to be a strict correlation between the same record numbers in different files, and you can also on just one JUMP command go 
to any record in any of the 32000 records in any of the twelve files and carry on cross-referencing from there onwards. 

DBMS'S MACROS WORK FROM THE MOMENT YOU INSERT THE 'TASK DISK' IN THE COMPUTER 
Simply design your file, give its fields your words, setup your report mask, and then enter your records. Switch to automatic drive' and 
formulated any task you wish to program to fulfill, the task is stored as a macro, Take a copy of the program on another task disk' and from 
then on r the task disk will function without a single key stroke. Think of a number of such task disks' such as ' 'stock-re-order reports"; 
"stock* valuation reports "analysis"; "patient history analysis"; "research-analysis"; "budgetting-analysis"; "vehicle-location 
control"; "librarian analysis"; "plus more?" 

Not only does this program surpass most of its kind that you might buy elsewhere, but if you buy the hardware from us, then you get it 
FREE . , , DBMS \\ (WITHOUT MACROS! AND DBMS III ARE FULLY IMPLEMENTED UNDER CPM-86 ftm) AND MS-DOS (tm) I.E.: 

SI RIUS/VICTOR/IBM DBMS II IS £ 39 5 , 00 (or £250.00 by mail order ex . training) , , , DBMS I II is £ 5 7 5, 000 (or £2 9 5 . 00 by mail order 
ex. training). 


MICRO-COMPUTERS 

INTERTEC 

■Supertnain&lK RAMOSE disks 

1BS6D0 


-Supefbrain.64K FWM<TOOC disks 

2395 CO 


■Carter 64KRAW32K disks 

219600 


■Goenaostar&SK RAM.-7D0K disks 

269500 

NORTHS! Afi 

-AdvanlageftK RAAITOOK disks 

enkw 

(tKcDOS) 

-Attsnlage S4K RAM53M disks 

E3C05JDO 

TTELEVtDEO 

-S02 64K RAM-7D0K disks 

2395.00 



395000 


-303 ^KRAY.'IQM disks 

519500 


416S6W9DK disks 

'rwinn 

ACT 

-Sirius 1 25&V12M disks 



-Sirius 2 36M2AM disks 

'£2695.00 


-Sirius 3 25SK/10MEG disks 

■£3996.00 

VICTOR 

40M256K/1-2M disks 

'£215600 

ISM 

-PCti£K FWAWfr disks- 

■E2796JOO 


-PCI 33CKS4CK disks 

'^JOO 

I0A 

XT (TEN MEGABYTE! 

E44U.D0 

IBM 

XF (FIVE MEGABYTE] 

(1500 

Ten m 


■^9500 


£3250 

ALTOS 

ACSerc^&iKRAM'lM disks 

2195.00 


ACSaXMO 20&VlH»*sg dbks 

5995.TO 

NFC 

APC12BKJWi«M<lsRS 

d-SllOC , 

COftVUS 

Concept 16 Wipe 

call.00 

SANYO 

690&iKftAM030K(Ssks 

H95JOO 

ABC 

MSitRAMimEisIcs 

sscuw 


A SI ttHttpjtsr prices- intiuds nr^jEic as standard 



All pricss marked 1 ar? 311-6 Wt machine*. 


WE STOCK mST OFTk E BEST MOWN SOFTWARE ALSO MOST OF THE BEST 

KNOWN BRANDS OF PRINTERS i PERIPHERALS FROM 30100 TO 

IpKV^NIDfiBNECOUMEANAOEXifliCOlC 



PRINTERS 

OKI 

-Microline 80 

295.00 


■Micro line 82 A 

305.00 


-Microline 83 

695.00 1 


■Microline 64 

805.00 

EPSON 

-MXBO/FT-3 

425.00 


-Mxioairr-3 

575.00 

ANADEX 

DP 9000 

895.00 


-DP 9501 

1045.00 


-DP 9501 {A) 

1 145.00 

QUWIE 

9/45 R/O 

1095.00 


-9(55 R/O 

2195.00 


-9/35 R/O 

1495.00 

NEC 

-3510 RIO 

1495.00 


-7710 R/O 

2195,00 


-5520 KSR 

Z2&0.00 

DRE 

■6620 

1295,00 


*6830 

1695.00 

TEXAS 

-810 

995.00 


-025 

095.00 

DIABLO 

-630 

1995.00 

RICOH 

-RP1600 

1095.00 

OLYMPIA 

-ESW 103 14 CPS 

975.00 


SYSTEM DEAL (aur speciality) 
[SAVES YOU 1500.00+ 


Buy any computer, any printer and 150.00 value 
diskettes add EOS. OO for cables and tasting, 
add 10% for return to base warranty tor 1 year (optional} 
add £ 1 1 0.00 for delivery & installation {optional) 
Training optional _extra £1 20.00 
and get completely FREE ■ ■ * 1 * 

cpm handbook SO basic exercises 2000 sheets paper 
DBMS HI. 7 magic wand w/proc magic calc 

mbasic 80 diagnostics msnrtJdSQrt 

recover autoload instant basic 

library boxs jisk/ggmes DT/ AS/NS sorts 

Total Value £1525.00 

Based on 8 bit hardware, 16 bit software varies. 
Here's a typical example of a complete system deal 
1 -Sirius 1 28k ram/ 1 .2 megabyte disks 23 95 . 00 

2- Qk) mlcr ofine SO printer 295 , 00 

3- Cables & testing 35.00 

4- Diskettes 1 50.00 

5- pDce differential on magic/ wand for word-star 1 00 . 00 
software described above ***** FREE ****"3025.00 
We specialise in 1 STANDARD MICRO PRINTER 
SYSTEMS' as well as 'NETWORK SYSTEMS BASED ON 

A SHARED HARD DISK'. 

The range of computer products (mostly ex stock) 
includes the most popular brands of micro-computers, 
printers, modems, buffers, spoolers and software. 


G.W, COMPUTERS LTD — Tel: 01-636 8210 
POPULAR BRANDS OF EQUIPMENT WE SELL 
M I OR 0 S: S frl u s/Vic tor/I . B.M. / D EC 
Eps o n / N orl h -s t a r/Sa nyc/S u p e r b ra i n 
Compu $1 a r/ A I tos / A pp le 4 Isa/T el ev) d e o 
PR I NT E R S: N ec/Q u me/Dj a blo/O k r/Ep s o n 
O lympi a/Ri co h/T exa s/ Dre/A ha de x 
OTHERS; Cumis/Compustar 
Hard disks networks and multiplexors 
S p o ol e rs/M o de m s/ Bu tiers 
most of the best known brands ol software 


SOFTWARE 


G .W.L -BUS V8-QQ (Accounts) 

-DBMS ll i Database) 

■ DBMS II (by mail order only) 
■DBMS III {database} 

-DBMS I FI (by mail order only) 

? FORMST EXT/C ALG'-DBM 5 I 1 


275.03 
*£395.00 
- £250.00 
‘ £575.00 
" E295-0G 
1 E575.CO 



■Sales Ledger 

*£95.00 


■Purchase Ledger 

*£95.00 


■Nominal Ledger 

*£95,00 


■Stock-Control 

■£95.00 


-Address- Mailer 

■£95.00 


■GAScnONSort (500 Rees/ Msecs) 

‘£95.00 

MICROSOFT 

■Mbasic SO 

*195.00 


-Fortran 50 

295.00 


-Cobol 50 

395.00 


-Basic Compiler 

*225.00 


-MU lisp/mu star 

125-09 

MICROPRO 

-Wordstar 

'£295,00 


-Mail-merge 

* £95.00 


-Spelslar 

125.00 


■W-sta rtM-merge/Sp-Star 

425.00 

BYRQM 

■BSlam {communications) 

100.00 


■SStms (teie-comms') 

100.00 1 

DIGITAL 

■CBasic 

75.00 


Concurrent CPM/66 

■375.00 


CBasicfiS 

■175.00 


-Pascal MT 

225.00 

LIFEBOAT 

■T/Maker 

155,00 

M TOC US 

■CIS Cobol 

420.00 


-Forma ll 

100.00 

SORCIM 

-Super Calc 

195.00 

PEACHTREE 

Magic Wand 

190.00 


-Magic Calc 

175.00 

VARIOUS 

-deluding lele-commselc 

calLOO 

Software formals or all micros In our hardware list. 

All prices marked £ ere available 8/16 bit fonrriats. 


SOFTWARE COMMENT! 11 


PERIPHERALS & 
ACCESSORIES 


CGRVUS -5 Meg hard disk 1950.00 

-11 Meg hard disk 2050.00 

-20 Meg hard disk 3950,00 

-Mulliplexor 7 station 695-00 

-Mirror backup card 695, 00 

I NT ERTEC -Compusl ar 1 0 Meg h ard d i sk 2950.00 

-CDC 144 Meg hard disk 7950.00 

N'STAR -16 Bi t u/grade 395.00 

■18 Meg hard disk 2995.00 

RODIME -6 Meg hard disk 1495.00 

■12 Meg harddisk 1950.00 

GENIE -5MG f I xerf/5 MG rem oveabl e disk 

3295.00 

QUA DR AM -64 K print spooler/copier 295.00 

BtZCOMP -RS232/ Auto-modem 1200 baud 450.00 

AST -port expanders (4 tmnls to i pm) 395.00 

GIX -port expander (switcher) 95:00 

NOTE; Corves drives with multiplexor may network 
struts , , Superbrain . . Concept . , PET . . Victor . . 

IBM . . 


INTEGRATED SOFTWARE IS PROPERLY 
REPRESENTED, when the degree of integration 
reflects the ability to refer to as many different flies, 
as well as employ as many different functions, 
under as many different modes as possible in one 
program only. This principle not being observed, will 
confer upon your purchases the attribute of their 
being expensive as an aggregate even though 
individually they are cheap. "DBMS 111.7" and "THE 
KEY" are comparably worthy of such a label. 


TERMS & ETC 

G. W. Computers Ltd (Grama (Winter) Lid) 

55 Bedford Court Mansions 
Bedford Avenue London W.C.T. England. 

Tel: 01 636 6210: 01-631 4BT8: llx 892031 two gj 
Boston office tlx 94 0690 
24 hour answerphorre leave address for intppacks 
We do not ope rale a reader’s reply card service. 
Terms: C.W.O. or C O D. Prices exclude V.A.T 
bui Include all non credii discounts available. 

No dealers. The above lists are not exhaustive 
Please Ciill at our showroom only by prior 
appointment. Unless expressly agreed, all 
warranties are commercial 90 days return 
to base for parts and labour. Annual 
warranties and main tenance facilities 
available nationwide through closely 
related third parties. 


TELEPHONES 01 636 8210 01 631 4818 TLX: 892031 TWCG (BOSTON 94-0890) 





AN IMPORTANT ANNOUNCEMENT 
FOR POTENTIAL SYSTEM BUYERS 


Any serious buyer knows that although the HARDWARE 
and SOFTWARE are both inter-dependant, the choice of 
software is CRITICAL to the consequence of having useless 
piece of hardware nor not. 

With this in mind our standard system deal gives you the 
software free with a system purchase. However, if you 
want morel 

NOW we have a piece of software that is a challenge to the 
highest state of the art on micro-computers today, it's the 
first of its kind world- wide. It is called THE KEY, and it will 
unlock the power of your micro to the limits of your 
imagination. It is very expensive however, because it is the 
first to embody many features of other programs, in one 
single program that has over- lapping functions. It costs 
995.00 Stg., and is available with a system purchase, 

it features, the entire list of functions already covered by our 
program called DBMS IIL7a to be seen elsewhere in our 
advertisement, PLUS, + + + + + + + + 

Paint any form including upwards from 1 00 (depending 
upon size of ram in hardware) data fields on the screen. 
Screen width up to 250 columns. Page lengths 1 00 lines. 

The form might be a letter where data fields on the screen. 
Screen width up to 250 columns. Page lengths 1 00 liens. 

The form might be a letter where data fields are name- 
addresses. Search files and accept any fields on teh 
database into any fields on the letter. The form might be a 
spreadsheet, where searches call records (in columnated 


style) from the database and perform calculations, the 
difference here is that unlike other 'calc' programs giving 
you 254 lines per spreadsheet, THE KEY gives you 32000 
lines if your database has that many records. 

The standard attributes of any field, allow you to SEARCH 
OTHER FILES for fields to accept into any field on the 
current form, plus allowance to POST OTHER FILES any 
fields from the current form into any fields on that file. 
RELATE TO AS MANY OTHER FILES, as the number of 
data fields you have on the master form. Make data fields 
CALCULATE AGAINST FORMULAE, and other data fields, 
VALIDATE DATA INPUTS criticially character by character; 
numerically, alphabetically and date-wise, 

NO MANUAL NEEDED, all help menues accessible by hitting 
'esc' at any point in the three major modes of activity 
(create, data entry, data query). 

You can set up dozens of individual files that eventually are 
inter-connected through one master form; like an invoice, 
order, personnel-file, stock control, mail shot. The master 
form may at every juncture of a data field, go outside the 
current form to supplementary forms for data retrieval, or 
post-filing. 

Come along the computing road with us. We're out in front 
so you'll get the best there is at the price. On IBM and 
SIRIUS. 

The first robot-concurrent-forms-database-text-processor- 
s preadsheet-no-man ual-allin-one- p rog ram , 


G. W. COMPUTERS LTD — Tel: 01-631 4818 

Contains the highest state of the art software available today 

FORMS/TEXT/CALC/DBMS IV ALL IN ONE PROGRAM - "KEY" - at £995 

When you budgetfor a complete system of software you eventually end up with a host of packages like, Sales, Purchases, Nominal, 
Data, Text, Calc, Mailshot, Invoice, Order, Workflow, Personnel, and so on. 

The list is endless and the outlay several thousands of pounds. 

Design a form as wide as a window of 250 characters, long as needed. Cursor movements are 'left, right, 
up, down, delete left delete right, tab right-left-up-down' Paint your form as you like directly on the screen. 

Write a letter as you see it on the screen, edit it then simply enter * P to print. 

Set into the form, your data fields, "££££££" and specific file-related activities, formulae and validation 
checks. 

Enter values and see the spreadsheet calculate itself. 

Search files for data to be inserted to fields specified. 

All the features of DBMS III, explained elsewhere in our ad. 

Here's an example of an invoice you might design for your stationery 

You could design your own spreadsheet, order form, statement, or any other kind of form that is required to fit your existing 

stationery. 


Features. 

Text.,,,., 
Calc 

Database. 


INVOICE <0>££££££££££C£ 


To £<1 >£££££££££££££ 
£<2>££££E££££££££££££ 
£<3>£££E£££££££££££E£ 
£ < 4 > £ £££££ £££££££ 


From: G W. Ltd 

55 Bedford Court Mans. 
Bed lord Avenue 
London W.C.I. 


£<5> £££££££££ 

Tel: 01-636 8210 

Dale <6>££.££ 

Tax point <?>££.££ 

Agent <8>£££ 

Quantity 

Description Cost 

Tax Total 


<9>£C£ <1 0>£E££££££££££££ <11>E£ <12>££ <13>£££ 

<1 4>££ <15> ££££££££££££££ <16>££ <17>££ <18>£E£ 

and so on... 

Tola! . ,.<19> ££££££ Tax , , . <20>££££ 

<??> items <1 >to < 5 > internal command to request name input, and then search an address file for details. 

<??> items <6 >to < 7 > request date input and validate, 

<??> item <8 > request agent number and validate range. 

< ??> < 9 > request quantity, validate range. 

< ?? > < 1 0 > request description, search file, accept, and calculate fields <11>, <12 >, < 1 3 > , if finished in- 

voice then calculate fields < 1 9 > and < 20 > 

Now comes the more valuable facility, you can provide the 'FORM' with file-related instructions, not only to request a 'console' in- 
put for a file search against names, and stock, but after the invoice Is finished the fields you have selected may be passed to 

related files. 

EG: Send fields <0 >, <1 >, <6 > , <7 >, < 1 1 > , < 1 2 > , < 1 3 > , < 1 9 > , <20>toa sales ledger. 

Then send fields <9 > , < 1 0 > , < 1 1 > , to product analysis file. 

Then send fields <0>,<1 > , <7 >, < 1 9 >, <20> to V.A.T. file 

Then send fields < 1 0 > , < 1 1 > , < 1 2 > , < 1 3 > to Nominal ledger. + Circle No. 1 26 

Available at present oniy on S1RUS/IBM PC, 



1 Choose your SUPER- 
BRAIN . Twin floppy disc,i 
hard disc ( W6) or multi' j 
user (COMPUSTA R) I 
models available. If you dorft a 
need a W6or multi-user / 
straightaway, donY M 

worry - you can always r A 
upgrade Liter on. JT * 


*4 f7 Leave 
I nothing to 
14/ chance. Add 
a 13 MB 

CARTRIDGE TAPE 
BACK-UP UNIT to 
give file-by file back up 
for your SUPER- 
BRAIN hard disc. 


6 Add on a 5 lA" ^ 
Winchester in I 
a separate box, I 
Whichever way you 1U 
do itj Icarus 
Winchesters give 5, I 
10 or 30 MB of disc Hj 
storage - enough to ™ 
accommodate up to 200 


JL Either upgrade 
your SUPERBRAIN 
by replacing one 
floppy drive giving 

\ a Winchester plus 
floppy con- 
figuration . . . 


<d Your financial 

Ilf ^ Tector 

XV/ decides to u$e 
SUPERBRAIN for 
“WhaE if . * .” budgetary 
calculations. Icarus 
supplies specialised 
software. 


Steps & Adders 

Start here with SUPERBRAIN 


3 You need to store 
greater quantities of 
data with faster access 
times so Winchester 
Disc Storage facility now 
required. If you started with 
a W6, move forward 4 
places. Otherwise . , . 


2 Each 

SUPERBRAIN 
comes with CP/M 
operating system, 
BASIC programming 
language, twin Z-80 
microprocessors and an 
RS-232 communica- 
tions port, 


separate items 
of in formation 
about each of 
300 individual 
customers/sales 
prospects or up 
to 60,000 stock 
control 
records. 


7 Your company moves 
to another part of the 
country to take advantage 
of regional development 
gram, SUPERBRAIN 
servicing well 
supported by 
Icarus nationwide 
dealer network. 


/V Enhance 

You can 

VJ performance Of 

J SUPERBRAIN 

now read 

and create , 

by addition of 

your own 


IBM 8” 

BOARD and 

format 

supporting software. 

floppy 

discs. 


f interchange ' 

facility required so 
external 8 rJ floppy disc 
drive added giving ability to 
transfer data 
to and from a 
mainframe 
computer. 


U Fit all vour existing 
SUPERBRArNSwith 


ICARUS multi-user chaining 
adaptor to take advantage of 
. COMPUSTAR facility. 


*4 A COMPUSTAR 
I V systemenables 
I fai you to establish a 
multi-user network of 
SUPERBRAINS, with each 
SUPERBRAIN connected 
into a central data store 
giving 10, 96, or 144 MB of 
storage. 


M SUPER- 
BRAIN: 
the game 
with no end. Our 
development 
continues as your 
business 
prospers, . , 


Y qu don’t need to throve a 6 to start . To 
find out more about S UPERBRAIN 
microcomputers and add-ons from / earn s, 
circle the reader reply number below or 
phone for full details. 




Computer Systems Ltd, 


Deane House, 27 Greenwood Place, London NW5 INN Tel: 01-485 5574. Telex: 264209 


'1'he harm S UPERBRAIN 
dealer network includes: 


CALIBRE BUSINESS SYSTEMS, 
87 Long Lane , West S mithfi eld , 
LONDON ECIA9ET. 
TelrOI-6061738. 

J Sl F GROVER LTD, 10 Barley 
Mow Passage, LONDON W44PH. 
Tel: 01-994 '6477 
HOME COUNTIES 
COMPUTING CONSULTANCY, 
Lyngen , OldhiU Wood , Srudham, 
DUNSTABLE, Beds LU62NF* 

Tel: (05 82} 872463 
STRATEGY BUSINESS 
SERVICES, Station House, 
UCKFIELD, East Sussex. 

Tel: (0825)4143 


THAMES VALLEY 
COMPUTERS, 10 Maple Close, 
MAIDENH E AD, Berks . 

Tel: (0623)23532 

TRANSFLO INSTRUMENTS 
LTD, Loose Road, MAIDSTONE, 
Kent ME 15 7BY, 

Tel: (0622)683888 
SOUTH & SOUTH WEST 

MICRO-XZEC LTD, Walton 
House, Richmond Hill, 

BOU RN EMOUTH , Dorset . 

Tel: (0202)21220 

EAST 

CAMBRIDGE MICRO 
COMPUTERS , Cambridge Science 
Park, Milton Road, CAMBRIDGE. 
Tel: (0223)314666 


CULLOVILLE LTD, Thomfield, 
Woodhill Rd, Sandon, CH ELMS FOR D 
Essex. Tel: 0245 413919 

MIDLANDS 

BASIC BUSINESS SYSTEMS 
LTD, Network House, 20 Ludlow 
Hill Rd, WESTBRIDGEFORD, 
Nottingham. Tel: (0602)232265 
MICROAGE LTD, 53 Acton Rd, 
LONG EATON, Nottingham 
NG10 1FR. Tel: (0607) 664264 
VIGO SOFTWARE SERVICES, 

Malt Shovel Cottage, Vigo, Burcoi, 
BROMSGROVE, Worts. 

Tel: 021-445 1445 



BORDER COMPUTING Ac 
PROGRAMMING, Dog Kennel Une, 
BUCKNELL, Salop, Tel: (05474)368 


MICROCARE COMPUTING 
LTD, 18 BanesweU Rd, NEWPORT, 
Gwent. Tel: (0633)50482 
NORTH 

AP LTD, Maple House, Mortkke 
Crescent, CHESTER, CHI 5UR. 

Tel: (0244)46024 
JENNINGS COMPUTER 
SERVICES, 55/57 Faglev Road, 
BRADFORD, West Yorkshire, 

Tel: (02 74) 637867 
MICROSERVE (Humberiide) 

LTD, 39 Oswald Road, 
SCUNTHORPE, South Humberside 
DN15 7PM, Tel: (0724)489696 
NA STAR COMPUTER SERVICES 
LTD, Ashton Lodge, Abercrombie 
St, CHESTERFIELD S41. 

Tel: (0246)207048 


SORTFIELD LTD, E Floor, 
Milbum House, Dean Street, 
NEWCASTLE-UPON-TYNE. 

Tel: (0632)359593 

XENON COMPUTER SYSTEMS, 
1 8 Old Rectory Gardens , Chcadlc , 
STOCKPORT, Cheshire. 

Tel: 061-428 9508 

SCOTLAND 

ESCO COMPUTING 
FACfLITIES, 321 Blythwood Court, 
Anderson Cross, GLASGOW G21, 
Tel: 04 1 -2 21 0310/2536 
TURNKEY COMPUTER 
TECHNOLOGY LTD, 10 Somerset 
Place, GLASGOW, Tel: 041 -332 7101 


• Circle No. 127 


PRACTICAL COMPUTING October 1983 








cirhnn the specialists in 

computer systems S100 SYSTEMS 


WOW IS THE TIME YOU SHOULD BE USING THE SI 00 FOR: 

UPGRADABILITY 
MODULARITY 
HIGH RELIABILITY 
UNMATCHED VERSATILITY 
AND AN INTERNATIONAL STANDARD 


OUR BRITISH BUILT MIDAS S1Q0 

SYSTEMS OFFER ALL THESE 
ADVANTAGES TOGETHER WITH 
CP/M 2 CP/M 86 
** AND NOW CP/M PLUS ** 

5i" and 8" FLOPPIES 
SINGLE OR MULTIPLE USERS 
FIXED AND REMOVABLE HARD DISCS 
TOTAL SYSTEM FLEXIBILITY 


CP/M + S100 


BOARDS 


We stock over 50 different SI 00 Boards all from quality manufacturers. Advanced Micro 
Digital, Godbout, SSM, Micrornation, Dual, CCS, Sirton, Morrow, Pickles & Trout etc. 


S100 CPU CARDS 


No 1 of a Series 


' Z80A or B SBC, 64K RAM, 2S + 2P, FDC, 2K EPROM, CTC. 

- Z80A Slave 64K or 1 28K RAM, 2S + 2P, 2K EPROM. 

1 Z80A 2/4 MHz, 2/4K EPROM 1 6/24 bit add, IEEE696. 

> Z80Aor B, 8K EPROM/RAM, 16/24 bit add, IntCont, IEEE696, 
h Z80A, Serial I/O, 2K Monitor 
■ 8085 + 8088 dual CPU Card, IEEE696. 
h 8086 + 801 3C, 1 6 bit CPU + space for8087, IEEE696. 

1 6800 + MMU, 8K ROM, 

• 16032 + space for 32K ROM + 16082, 16201, 16081. 


We are pleased to discuss your requirements and will advise you as to whether your 
needs can be met with one of our computers, 

AJI of our systems are specials as they are configured to suit your specification, thus 
ensuring that you get what you want rather than what happens to be available. 

Write or phone for a catalogue. 

Unit 14, 29 Willow Lane, Mitcham, Surrey 
Telephone: 01-640 6931/2/3 


irhnn 


computer systems 


PRACTICAL COMPUTING October 1983 


• Circle No. 128 

43 






a MicroSiqht a 

Use your BBC Model B as an image analyser with 

MicroSight I 



Available on BBC, Apple, Commodore, Research 
Machine, Sirius, etc, Includes Camera cables, interface, 
software and documentation. 

£495.00 + VAT 



MicroScale. 


Image processing software to calculate area and 
perimeter of objects within a specified window also 
to dimension features. Disk and primer dumps of 
binary and grey scale data. 

£295.00 + VAT 


MicroEye Vision Interface. 



256 x 256 pixel resolution with 255 grey levels per 
pixel comes complete with software and document- 
ation. Can be used for video tape digitising Satellite 
picture analysis etc. Available for BBC, Apple, 
Commodore, Research Machine, Sirius etc. 

£295.00 + VAT 


DiGiTHURS 


Digithurst Ltd. 

Leaden Hill, Orwell. Royston, 
Herts SG8 5QH 

Tel: (0223) 208926 


• Circle No. 129 



SPECIALISTS IN THE MAINTENANCE OF MICRO COMPUTER SYSTEMS 

including: 

APPLE - IBM PC - SI RUS/ VICTOR 

ICE’COHVUS VLASAK- EICON QUME ■ A MADE X EPSON CENTRON 1C ■ TEC 


COMMERCIAL DATA SYSTEMS LTD 

DOWN HAM ROAD, RAMSDEN HEATH. E I LLEFHC AY, ESSEX. CM11 1PU. TEL: O»e.7102$2, 
ST. JOHNS COURT. 8ACUP ROAD, flAWTE U STALL. LA NCS. 064 7PA. TEL: 07W21$0«. 



2 WABSTONE PARADE. HOCKLEY. BIRMINGHAM. TEL: 021-236- 
65 LODGE CAUSEWAYS, FISHPONDS, BRISTOL. TEL: 0272456424. 



• Circle No. 130 


EPROM PROGRAMMERS 


BBC 


PET VIC APPLE ACORN 


MODEL A 271 6. 251 6, 2532. 2732, 2732A, 2764, 2564. 251 28, 27123 

£110 00 

MQOEL B 271 6, 2516, 2532 £53.50 

MODEL C 2716. 2516. 2732 £53.50 

PET , VIC. ACORN MODEL A. B. or C ALL PROGRAMMERS CAN 

R E AD/PR OG R AM M E/V E RIF Y (CO P Y 
BBC.Appte Model A only. 

Full Software Tape supplied for your Computer 

PET OWNERS:- Free Programme for making your own Character Sets. 

PET SUPERBOARD 40 or 00 COLUMN E 52.50 

• Select up to 8 ROM/Eprom, RAM/ROMS from any available ROM Socket. 

• No Wires, Switches or Soldering Required. 

• Will except any combination of 2K or 4K ROM/EPROMS, RAIWROMS. 

• Select upto S of your own Character Sets 

APPLE VIA BOARDS *The Via Board contains 1 or 2 6522 Vla's Single £27.90 
fgj f 5 2 : 2 v ™' s contains: 2 x 3 brt FYogr ammabte f/O Ports, 1 *8 Bit Shift Register Double 
L36.60 

• Four Handshaking Lines CA1 CB1. CA2, CB2. Two Programmable Timers. 

• Full 5622 Data Sheets supplied 

ACORN MDNrTOR CHIP (2K( £ 1 0 . 50 

• 1 0 Commands to simplify Machine Code Programming 

• Full Screen Editor. Repeat Key. Auto Entry Flashing Cursor. Tape Verify, 

• Slow Scroll. Memory Fill, and many more. 

PET IEEE PRINTER BUFFER Available soon 

I FEE -Centronics - RS232 

• Free Your Pet from Printing 

• The Printer Buffer receives all your Printer Data in seconds 1 5 sheets] Then outputs your 
Data whiieyou type your next letter. 

• 14K printer Buffer. 

• Full IEEE to IEEE or IEEE to Centronics output. 

• IEEE to RS-232 options] extra . S.A,E. for details 


CONNECTORS 
PET IEEE User Port 

£5.65 

VIC User Port £5.65 
VIC Games Port £5.65 
Acorn Expansion Port 
£7.00 

PET Cassette Port 
(Crimp} 

Order s over 1 00 £1.00 


2716 EPROM (2KJ 

£4,00 

2532 EPROM |4K) 

£6.50 

2764 EPROM [SKi 

£ 0.00 

61 16 P,3(2KJ Static 
RAM £4,50 

6522 VIA'S £6.50 


CIO Cassettes [10) 

£5.00 

Eprom Eraser £40.00 
Eprom Eraser Timer 

£ 10.00 

ALL THESE PHICES 
INCLUDE VAT AND 
P&P 


Please Add 15% VAT Plus £2.50 P&P to your orders. 

OFFICIAL ORDERS 

CId COMPUTER INTERFACE DESIGNS 
4 ALBERT RD. MARGATE. KENT. (0843} 294648 


'Circle No. 131 


PRACTICAL COMPUTING October 1983 





Package 


C Drive 
Monitor 


opleUe Compute^ 

^ah Resolution^ 


2Sk= 


The market 

% 

leaders!... 


ATA’S philosophy is to 
ensure that our 
customers have quality 
computer hardware and 
software products at 
COMPETITIVE prices, 
together with technical 
assistance required to 
efficiently operate their 
computer system. 

Export specialists — ring or telex for details 


£.wfth recognised professional support 


Kappro II £ 

FRESH FROM THE U.S.A.! The best value Portable 
Micro from Kaypro . . . Includina Software 

KAYPRO II 2 x 200K disc drives 1695.00 

KAYPRO IV 2 x 400K disc drives 1 950.00 

KAYPRO XI x 400K disc drive and built 
in 20MB Winchester 
Other Software including financial 
ledgers etc also available. 

Hyperion 


Hyperion 256 x 2 MSDOS, BASIC £2950.00 

Printers & Plotters 
Epson 

Epson RX80 1 20 CPS 260.00 

Epson FX80 160CPS 350.00 

Epson MX 100 100CPS 420.00 

Apple 

Apple Dot Matrix 1 20 CPS 349.00 

Apple Letter Quality Printer 11 99.00 

Ricoh 

Ricoh 1 300 Flow Writer 1 099.00 

Ricoh RP1 600 Flow Writer 1499.00 

Mannesmann Tally MT1 60L 550.00 

Mannesmann Tally MT1 80L 690.00 

Plus full range of Centronics 
Printers Available. 

Plotters 

Hewlett Packard HP7470 1066.00 

Hewlett Packard HP7475IA3) TBA 

Calcomp 8 PEN (A3) 2999.00 


Interfaces £ 

Apple RS232 Super Serial card 99.00 

Apple IFEE 488 card 205.00 

Apple parallel interface with cable 99.00 

Apple III parallel interface with cable 1 30.00 

CCS 7710-01 RS232 serial interface 109.00 

Grappler + parallel graphics interface 105.00 

PACT 8 bit A/D converter 1 1 5.00 

Keyzone 1 2 bit A/D converter 1 38.00 

PACT 1 2 channel D/A converter 1 25.00 

RGB card TTL/analog output (programmable) 99.00 
RGB card TTL output 85.00 

Digitek Accessories & Interfaces 

64K RAM 199.00 

1 28K RAM 299.00 

PrintMaster parallel printer 75.00 

interfaces available for 
Anadex, Epson, Centronics, Citoh, 

NEC & TEC 

Super PrintMaster III interface 100.00 

available for all printers 
as above and also fer the 
Apple Dot Matrix printer 

RS232 high speed serial interface 80.00 

Z80 with manuals 149.00 

Screenmaster 80 inc. soft switch 1 85.00 

inverse video, 3 scroll speeds 
& altern. chr. sets 

Eurocolour card with modulator (]( + ) 95.00 

UHF Modulator with 'clean signal' 39.00 

Robocom Bit Stik C.A.D. Graphics 
System 

Robocom Bit Stik 1.1 system 230.00 

Robocom Bit Stik 1 000 upgrade software . 1 90.00 
Robocom Bit Stik 1000 system package ... 41 5.00 
Plotter driver for A4 and A3 plotters 90.00 


Apple Hardware £ 

Apple lie 

Apple lie 64K 645.00 

Disk drive with controller 270.00 

Disk drive 200.00 

III Monitor including stand 1 20.00 

Phoenix hi-res green 12" monitor 99.00 

Phoenix hi-res amber 1 2" monitor 1 05.00 

Apple III 

Apple III 256K including Monitor III, 1 980.00 

Disk drive & SOS 

Additional 5.25" diskdrive 270.00 

Profile 5mb Winchester 1495.00 


Accessories 


80 column card 65.00 

80 column card 64K extended 1 45.00 

Numeric keypad (//e) 85.00 

Numeric keypad <]( + ) 75.00 

T.V. modulator with sound 1 2.00 

Videx Videoterm 80 column card 195.00 

Videx Soft Switch (40/80 column) 20.00 

Videx Keyboard Enhancer 87.00 

Videx Inverse ROM and character sets 1 8.00 

Microsoft Softcard (Z80 CP/M) 199.00 

Microsoft Softcard Apple III (Z80 CP/M) .... 265.00 
Accelerator card (3.6 mHz 6502C & 64K) . 289.00 

Joystick <//e) 29.00 

Joystick (]( + ) 22.00 

System Saver fan & voltage reg 59.00 

Dust cover for Apple II 6.50 

Dust cover for Apple II 2 x DD & 1 2" minitor .. 9.00 
Dust cover for Apple III & Monitor III 1 1 .99 

Colour Monitors 

Luxor high resolution 

25Mhz linear & TTL 499.00 

Kaga Denshi medium resolution TTL 325.00 

Kaga Denshi low resolution 265.00 


We also stock the Hantarex RGB monitors, as 
recommended by Apple in Europe. 

PRICES EXCLUSIVE OF VAT AND CURRENT AT TIME OF 
PRINTING 


WE ALSO STOCK APPLE 


AND HEWLETT PACKARD 

■■■ 




TERMS AND CONDITIONS 

For delivery please add 
£0-£199 + £5, £200-£1499 + £13, 
£1500+ 1V?%. 

CHEQUES WITH ORDERS 

Please allow 1 0 days for clearance 
PLC's, public sector etc 30 days 
credit available on official orders, 
subject to 5% m ,, .m hhi 
credit charge. P. 1 


ATA - LONDON 4 Albion Hse f 
1 Back Hill, London EC1 . 01 -833 0044 
Telex 251 02 CHACOMG 


PRACTICAL COMPUTING October 1983 


• Circle No. 132 

45 










S9 XX \ ^ e lc^!a#°to^ S 

^£>V 


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ie\®*' 


• Circle No. 133 


EXTRA SOFTWARE, , EXTR 

More good news as Osborne leads the way yet again with a 
sensational new software extra. Two leading programs - 
Personal Pearl and Peachtree Business Management Systen 
together worth over £600.00 come free when you buy either 

of the following systems. 

THE OSBORNE 1 
BUDGET OFFICE SYSTEM. 



The Osborne 01 delivered with five 
outstanding software programs 
Ready-to-go - 

Supercalc: Electronic spreadsheet 
C Basic: Programming language 
M Basic: Programming language 
Wordstar: Word processing with Mailmerge 
CP/M: Operating system 

As well as giving you Personal Pearl an 
Peachtree Business Management systen 
Osborne include STARTPAC 
in the 01 Budget Office System. 

This self-instruction guide will 
enable you to get to work with your 
Osborne straight away! 

Osborne offer you the 0 1 Budget Office 
System for only £ 1495.00. A saving of neark 
£ 600 . 00 . 



THE OSBORNE 1 
EXTRA STORAGE SYSTEM 


The proven Osborne 01 and the Trantor 5MB 
lard disk offer the storage capacity of more than 
0 times that of a floppy disk. And t 
aster system performance. The Ext 
system transforms the 01 Portable 
Computer into a powerful office syj 
natches the storage, speed, conver 
lexibility of desk top systems costii 
he price. Personal Pearl extends t 
)f your Osborne for information ha 
asks previously reserved for larger 

Installation is easy - simply ur 
iisk, plug it into your Osborne 1 an 
nstallation procedure. 

The Osborne 01 with Trantor 
>MB hard disk system together 
vith Personal Pearl and 
’eachtree Business 


Management System costs 
>nly £2995.00. A saving of 
>ver £ 800 . 00 . 



/ /// II I I 



Someone has to lead the way 


• Circle No. 134 




The SPRINT 1H 

with the Qume Conn 


Qume’s legendary print quality is now 
available for your small business or 
personal computer with our new 
SPRINT II PLUS daisywheel printer. 
The secret is The Qume Connection 
interface module. Our first Qume 
Connection modules fit the most 
popular computers, including those 
from IBM, Tandy, Commodore, Xerox, 
Hewlett Packard and Sirius through 
outrange ofR.S.232C, I.E.E.E. 
and Centronics interfaces. 

Qume Connection modules for other 
microcomputers are on the way. You can 
get the SP RINT 11 PLUS that’s right 
foryourprinting requirements, with a 
choice of 40 or 55 cps. So make the 
Qume Connection by calling us or one of 
the authorised Qume distributors listed. 


imm odore 


AUTHORISED DISTRIBUTORS 


Access Dara Communications Led,. 
Uxbridge, Middlesex, Tel: (0895)59781 

Alpha tech Computer Systems Led., 
Ron me End, Buckinghamshire. 

Tel: (06285)28217 

Bytech Ltd., 

Earlev, Reading, Berks. 

Teh (0734)61031 


Daisy Term i nais L td . , 

Haywards Heath, West Sussex. 

Tel: (0444)457546 

London Office -Tel: 01-434 2821 

ISG Data Sales Ltd., 

Reading, Berks. Teh (0734) 884666 

Facie Data Products Ltd, , 
Rochester, Kent. Teh (0634)401721 


i □ume 

* Qume (UK) Limited, 

Bridgewater Close, Reading, 
Berkshire, RG31JT 

Te!: Reading (0734) 584646, Telex: 849706 

A British Company of III 


50 


• Circle No. 120 

PRACTICAL COMPUTING Octcber 1983 



ATTENTION V1SICALC USERS! 


WITH VIDEX ULTRATERM VIDEO CARD AND 
ULTRATERM VISICALC PREBOOT DISK, YOU CAN 
SEE DISPLAYS THAT YOU’VE NEVER SEEN BEFORE. 


24 lines x 80 cols, 48 lines x 8 cols, 32 lines x 128 cols, or 24 lines x 
160 cols can be viewed on a LONG PERSISTENCE PHOSPHOR MONITOR. 


VIDEX ULTRATERM £299 ULTRATERM APPLEWRITER PR E-BOOT £21.27 
ULTRATERM VISICALC PRE-BOOT DISK £50.60 





BASF QUALIMETR1C 
FLEXY DISKS 

5f SINGLE SIDED/SJNGLE DENSITY 

1 1 BOXES FOR THE PRICE OF 10 ! I 

BUILT FOR ETERNITY 
WARRANTED A LIFETIME 

1 1 boxes for , i , • k » * » , .£165 


COPY II PLUS for APPLE & 
COPYII PC for the IBM PC 

An extremely sophisticated bit 
(or nibble) copy program to allow 
you to make back-up copies of 
your protected software. 

Also includes: 

Catalog, with file lengths, hidden 
characters, deleted files, Verify 
Disk-bad sector scan of disk, 
Verify Files-scan of individual 
files. Verify identical files- 
compares files on different disks, 
lets you know at what point they 
first differ. 

Verify drive speed: track/ sector 
map, Sector Editor. 

COPY II PLUS £39 
COPY II PC £39 


LK, VERSION 
SPECIAL PRICE £149 

The friendliest, most powerful 
electronic worksheet you can 
buy. Saves time in management 
and planning. 




Accelerator II 

MAKE YOUR APPLE RUN 
3,58 TIMES FASTER 
FOR ONLY £299!! 

Over 2000 UK Apple users now 
waste less time by using the 
Accelerator in an Apple. 

See what Richard King, Hardware 
Editor of PCN has to say about 
the Accelerator, {PCM 15.6.83} 

"Power down , open Apple , find 
empty slot, insert board , shut 
Apple , power up. That's it ~ 
well almost There certainly 
can't be many add-ins to the 
Apple system that make such a 
difference in performance with so 
little fuss." 

"The Accelerator II makes such a 
big difference to the operation of 
the Apple that l wish it did more. " 

"So what don't I like about the 
Accelerator II? Not a fot, to be 
honest It's simple to install, it's 
reliable , it's easy to use and It 
runs like a bat out of hell/' 

"For the real business user who 
wants a real increase in through- 
put I would strongly recommend 
the product " 



NOW 

AVAILABLE 
FOR 

EPSON MX 100 £4.45 

EPSON FX80 £3.95 

EPSON MXSO £3.95 

When ordering please state 
printers model 


SUPER SUMMER CLEARANCE SALE 

BUY NOW WHILST STOCKS LAST 




Adventure 4+5+5 . 

Adventure 7+8*9 

Adventure 10+ 1 1+12 

Poker 

Smurlcrm BEJ column eyrd 
Super cj!c tor ALS Z^Card 
Lurocolor Card . 

Parallel In ter tare 
Universal Fata In 
Dal stones of By 
He l! tare Warrior 
Star Warrior . . . 

David’s Midnight 
Red Alert . . 

Spate Quarks 
Cl atactic Tu 
Galactic Revo 
Dueling Dibits 
Labyrinth , . 

Raster Blaster 
Lower Caw 
Co urn y Fai 
Thief . . 

Swashbuckler 
Miss inf Rinf . . 

Pip Fen 

Space Strike lor IBM 
Terrorist 
Network 
Win did II . 

I. Lite 80 Col 
Russki Puck 
Phaier I ire 
Zenith 
Neptune 
Utter Silk 
High Orbit 

Data Master 3.3 

Job Cortuol/Costinjt in Pascal 

Transit (Utility) 

Zork II For IBM 

Easy planner for IBM 
Lasy writer 4Q eoli 
(tasy filer for IBM 
Juggler 
Transfer 
Grapple. 

Lower Case Apa 
Alien A in hush . 

The Best ot' Muse 
E-'irebuf. . . 

Frazzle . . 

Pegasus. , . 

Soi l pom Ad 
Cross Fire 
Jaw break 
Missie 


. 17.95 
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39.0D 
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69.00 

99.00 
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19.95 

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15.00 
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39.00 

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l 29.00 

49.00 

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14.95 

59.00 

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n 95 

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. , 7.95 



Mystery House 
Ulysses & The Gu 
Wizard & Princess 
Marauder. . . . 

Cranston Manor 
Threshold . . 

Mouskaitack 
The General .•iuuk^i 

iToff er 

Cannonball Blitz 

LatTpak 

I rt>feer IBM , 

Lunar Leepcr ...... 

Crossfire IBM 

Multi-Disk Catalog III 3 0 95 

Back II Up ... 24,95 

Phantoms hive . , 12.95 

Gamma Goblins . . ■ ■ 12-95 

Sneakers 12-95 

Autobahn . 12.95 

Dory , 12.95 

Space Eipgs , . . . 12,95 

Copts and Robbers 12-95 

Epoch 14.95 

Hadron 14.95 

ti 1 Draw 19.95 

Twerps 1 1 os 

Compuier Football . . 

Jellyfish - . 

11} Wars , 

Cyclop 
Bandiis 
Minotaur 
The Blade 

Call to Arms for IBM 

Escape from Runfi start I 3.95 

Free Fall I 3-95 

Smith Corona TP1 D/W Parallel 149,00 

Su percale lor IBM 149.00 

ACF- 1 Applesoft Command Lid i tori . . . 17,95 

Vluneli-o-Buf 22.95 

Routine Machine 29,95 

A ION Serial Parallel J/T 119 00 

AS IQ Apple Serial Card 79,00 

Mill Assembler Dev Software 45.00 

Cartels and Cutthroats 17.95 

Program Line editor L 8 95 

Oddcssy 14 95 

Global Prof rani Line l-.tlilor . . ... 29.00 

Kraut 39.00 

SupCT Kram . 69.00 

Leaver Case Chip .. 15.0(1 

Lower Case Adapt for pro Rev 7 , , 17.00 

Wizard SOB . 1 6K Buff Serial 1, 'I . 1 4 9. Oil 



Pete J|L Pam Computers 


0 


tnvi 




„ . London Retail: 

Mail Order 3 Distribution: 103-5 Bleqborouah Road 

New Hall Hey Road, ... London. SW1 6 6DL 

Rossendale Lanes. . BB4 6JG Norwegian Agent: Phone ; 01 -677 7631 

Phones: The Norwegtan Software House London Office 

{ 0 706 ) 2 1 232 1 & 2 2 7 0 1 1 Add res s 0 kernve ien 1 4 5 0pen Saturdays 

Telex: 635740 Petpam G Oslo S 



Telephone 47 2 64 65 77 

Prices do not include VAT please add 15% to your remittance 
Postage and Packing FREE 



• Circle No. 136 





* Circle No. 139 

PRACTICAL COMPUTING October 1983 


CRYSTAL RESEARCH LTD 


XTAL BASIC 3 

A Z80 based Interpreter. Disc and Cassette versions in- 
cluding CP/M are available now or in the near future. 
FEATURES 

1 Has over 110 Commands and Functions and is user extendable, 

2 Xtal BASIC 3 incorporates its own editor that is independent of 
VDUorterminal being used butappears to have the facilities of the 
most sophisticated direct screen editing, in brief the editor contains 
the following: 

Lines of 127 characters (can be extended up to 254) 

Full on screen editing, up, down, left, right 
Auto insertion of lines. 

HOME CURSOR, CLEAR SCREEN, DELETE LEFT, DELETE 
RIGHT, INSERTCHARACTER, ERASE WHOLE LINE, ERASE 
TO END OF SCREEN, PRINT SCREEN CONTENTS TO 
PRINTER, and ABANDON LINE. A LINE EDIT MODE IS IN* 
CLUDED AS STANDARD. 

3 Variables can be of any length. First five characters used to dis- 
tinguish one variable from another. Multi-dim arrays, string arrays 
and integer arrays, 

4 Full Tape and Disc file handling 

5 32 standard error messages and traps. Ability to trap BREAK 
KEYS. Error table is extendable. 

6 Possible to run programs larger than memory capacity, 

7 Special features allow transfers of programs from machine to 
machine 

S Xtal BASIC 3 is designed to be compatible with most available 
BASICS and a program is supplied for many BASIC to BASiC 
conversions. 

9 The manual, consisting of over 10Q pages, includes full description 
of the BASIC, sample programs, useful Machine Code Subroutines 
in Xtal SASIC 3. examples of extra commands and functions, 

10 SIZE 12K to 14K depending on the System. 

11 Available on Cassette and/or Disc. Please contact Crystal 
Research Ltd., for availability on your particular machine. 

12 On Cassette £40.00 4- VAT On Disc £60.00 4- VAT 

OEM and Manufacturers are invited to contact Crystal Research 
Ltd., for licence details. 


Open 0930-1200 1300-1730 except Saturday & Sunday 
40 Magdalene Road, Torquay. ^ L 

Devon. England Tel: 080327890 XTAL 

Access and earclaycard 

• Circle No. 137 


rofton 


Minins 


IT'S A BETTER BUY THAN MOST AT 
LESS THAN £4 PER MHZ. 

THE PRICE IS AS CRISP AS THE IMAGE. 
ORDER TODAY- WE'LL SHIP RIGHT AWAY 
All major Credit Cards accepted. 

Phone for details of cased and open 
frame monitors. 

CROFTOIM ELECTRONICS LTD. 

35 GROSVENOR ROAD, TWICKENHAM, MIDDX 01 B91 1923^ 1513Tetex 295093 

• Circle No. 138 


CAMDEN 

THE COMPUTER PEOPLE 


COMPUTER SYSTEMS LIMITED 

462 COVENTRY ROAD, SMALL HEATH 
BIRMINGHAM BIO OUG 

Telephone: 021-771 36,76 (10 lines) Telex: 335909 (Camden G) 


5mb WINCHESTER 



- w _ 


■ ■' l 

rr 

fa 4m » 



i t 

1 1 

W.S 

■H 

- 

1 



_ err". ™. - : 1 


SPECIAL OFFER 

APPLE 1IE PLUS MONITOR AND STAND 
5 MEG WINCHESTER WITH BUILT-IN 
FLOPPY. 


RECOMMENDED PRICE 
OUR PRICE 

10 MEG VERSION 


£2810 

£1995 

£2275 


ALL PRICES EXCLUDING VAT 



RRP 

CAMDEN PRICE 

APPLE HE 

845 

645 

80 COL CARD 

80 

70 

80 COL + 64K 

180 

150 

MONITOR & 

STAND 

170 

150 

DISK WITH CON 

345 

270 

DISK W/OUT 

245 

220 

TRIDENT 5 MEG 

1450 

1150 

TRIDENT 5 MEG 
PLUS FLOPPY 

1700 

1465 . 


12 MONTHS PARTS AND LABOUR ON ALL APPLE AND TRIDENT PRODUCTS 



* BETTER VALUE MAIL ORDER SUPPLIES FOR YOUR MICRO* 


(VEREX DISKS 




fDATALIFE DISKS) 


XIDEX DISKS 


"N 


(THE LAST ONE 





Manufactured by Verbatim, to accepted 
industry standards. Full one year warranty. 
Quality products at popular prices for both 
home and office use 


5.25 DISKETTES 

MD200-01 S/S. S/D. 48TPI. £1.71 

soft sector only 

MD200-AS S/S. S/D. 48 TPI £1 .66 

Apple systems only 

8 DISKETTES 

FD34-1500 S/S. S/D £1.85 

DD34-1501 D/S. D/D £2.82 

32 hard sector available at same pnce 

V J 



From Verbatim, the world's leading diskette 
manufacturer. Full 5 year warranty. All 
minidisks are certified for double density 
recording, and are fitted with hub nng 
reinforcement as standard. 

5.25 DISKETTES 

MD525 S/S. D/D. 48 TPI £1.92 

MD550 D/S. D/D. 48 TPI £2.86 

MD577 S/S. D/D. 96 TPI £2.69 

MD557 D/S. D/D. 96 TPI £3.60 

48 TPI suitable for 35 or 40 track operation 
96 TPI suitable for 77 or 80 track operation 
10 and 16 hard sectored versions available 
at same prices. 


j W&mSbLi 



The new premier quality standard, against 
which all olher manufacturers will have to be 
judged. All products certified for double 
density recording Now with a lifetime 
warranty. Unreservedly recommended. 

5.25 DISKETTES 

5012-1000 S/S. D/D. 48 TPI £2.06 

5022-1000 D/S. D/D. 48 TPI £2.90 

5012-2000 S/S, D/D. 96 TPI £2.92 

5022-2000 D/S. D/D. 96 TPI £3.77 

48 TPI suitable for 35 or 40 track operation. 
96 TPI suitable for 77 or 80 track operation 
to and 16 hard sectored versions available 
at same prices. 


8 DISKETTES 

FD34-9000 S/S. S/D £2.75 

FD34— 8000 S/S. D/D £2.80 

DD34-4001 D/S. D/D £3.26 


32 hard sectored versions available at same 
prices 


8 DISKETTES 

8012-1000 S/S. D/D £2.78 

8022-1000 D/S. D/D £3.36 

32 hard sectored versions available at same 
prices. 


V 


j 


THEMSTONE 

THE UiSTCNE 


th ehstc ne 

IHEW32JE 


Got a computing problem? Produce your 
own solution by using The Last One. a 
program generator which has helped to 
solve hundreds of problems in installations 
throughout the world. 

TLO runs on the Apple II and lie. 
Commodore 4032 and 8032/96. TRS-80 
Model ll {TRSDOS or CP/M), most CP/M. 
CP/M86 and MS-DOS machines including 
the IBM PC ( PC -DOS) and Sinus. 

Try out TLO for £50. 

A limited demonstration version of TLO is 
now available for only £50. including full 
documentation. This cost is fully refundable 
against your subsequent purchase of a full 
version. 

Full version costs:— 

for Apple II — £185 

all other versions — £330 


Please specify version requirements when 
^ordering. 


(diskdrive 

HEAD CLEANING 



Helps to protect your valuable data, and 
minimise expensive downtime and repair 
costs Consists of a flexible jacket, which 
receives a pro-saturated cleaning disk 
Each disk is sealed within a foil sachet to 
ensure that it contains the right quantity of 
cleaning fluid when used After use the disk 
is disposed of. and the jacket is kept for 
future use 

suitable for single or dual head drives. 
Please specify 8 or 5.25 disks 

STARTER KIT £8.12 

(contains jacket and two cleaning disks) 

REPLACEMENT CLEANING 

DISKS £15.54 

(pack of 10) 


DISKETTE 

STORAGE 

BOXES 



Protect you r diskettes and valuable data 
from external contamination. Lockable, 
portable and secure Two part box made 
from anti-static ABS plastic. Price includes 
dividers and index labels. Capacity 80 disks. 

A5 Storage box (for 8 disks) £33.60 
A6 Storage box (for 5.25 disks) £23.10 


CTI - CP80 
PRINTER 



Features:— 

Friction and tractor teed as standard 
80 c.p.s 

Bi -directional logic seeking. 

1 3 x 9 dot matnx giving true descenders 
Sub and superscripts. 

Italic printing and auto underlining 
Condensed, emphasised, expanded and 
double strike printing (can be mixed m a 
line). 

Parallel interface fitted as standard. 

12 month warranty. 

Print sample available on request 


CP 80 PRINTER £289.00 

Optional RS-232 interface £40.00 

Special VIC20/VIC 64 interface £46.00 

V ) 


(printer stand! 



Suitable for use with dot matnx printers Lifts 
printer sufficiently to enable continuous 
stationery to self-stack Painted steel unit 
Dimensions 39cm wide 
x 28cm deep 
x 10cm high 

Comes as package which also 
contains:— 

200 sheets continuous stationery 
1 x 9 Vi binder 
1 x highlighter pen. 
choice of rubber feet/sticky pads. 

PRINTER STAND £21.95 


J 


COMPUTER 

FURNITURE 



Suitable for use with ail leading personal 
computers. Features a top shelf for monitor/ 
printer, lower shelf for books, paper and 
general storage; large desk top surface at 
keyboard height; attractive teak finish, and 
castors for mobility. 

U.K Manufacture. Comes in flat pack for 
self assembly - full instructions provided 

A further range of more sophisticated units 
is available - please ask for details. 

^ THE ORGANISER £55.00 


^To: DISKPOST, FREEPOST. WEST MOLESEY, SURREY, 
| KT8 0QF. Tel: 01-941 4066 

I Qty Product Price 


All prices inclusive of delivery and insurance on British 
mainland. 

YOUR NAME 




PC Sub Total 

Dellvery/lnsurance 
V.A.T. 

TOTAL VALUE OF CHEQUE PAYABLE 
TO DISKPOST 


FREE 


Company Orders 

If you are unable to raise cheques without an invoice, please post or 
telephone your order to us . We will then forward a pro-forma invoice. 
V for your accounts department to pay against. 


ADDRESS.. 


Tel. No.: 

Please charge to my Vlsa/Mastercharge/American 
Express/Diners Club account. 


My card number is 

BP /Tjm DINERS CLUB g 
[ vrSA I (< I » INTERNATIONAL fl 

Credit Card Orders 



We welcome Visa. (Barclaycard). Mastercharge. (Access). Diners 
Club and American Express. There is no credit card surcharge. 
Either write your card number on your order, or telephone your order 
to our sales office 


J 


DISKPOST' is the mall order division of the BFI Electronics Group 
Europe’s largest independent diskette supplier. 



FREEPOST West Molesey 
Surrey KT8 0QF. Tel: 01 -941-4066 

• Circle No. 140 


53 


PRACTICAL COMPUTING October 1983 






If you think seriously 
about Micros 



54 


PRACTICAL COMPUTING October 1983 



S5 


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TO CUAR OUR CURREHT^OCK 

for TUT au.uk 

W ILL MUffl 


RING OUR HOTUNEoi -206 0440 
ASK FOR JACK GOODMAN 
OR KEVIN WOODS 






PRICE 

With 




V.A.T. 

CMB4032 

Micro Computer 

32K RAM €495.00 

£569.25 

CBM 8032 SK 

Micro Computer 

96K RAM £675.00 

£776.25 

CBM 8096 SK 

Micro Computer 

96K RAM £795.00 

£914.25 

CBM 9000 

Micro Computer 

1 28K RAM £795.00 

£914.25 

CBM 2031 

Single Disk Drive 

170K/B £295.00 

£339.25 

CBM 4040 

Dual Disk Drive 

340/K/B £520.00 

£598.00 

CBM 8050 

Dual Disk Drive 

1 M/B £670.00 

£770.50 

CBM 8250 

Dual Disk Drive 

2M/B £895.00 

£1029.25 

CBM 4022 

Printer 

Tractor Feed £345.00 

£396.75 

CBM 4023 

Printer 

Dual Feed £345.00 

£396.75 

CBM 8023 

Printer 1 60cps 

Tractor Feed £625.00 

£718.75 

CBM 6400 

Printer 4 5cps 

Daily Wheel £995.00 

£1144.25 


L&J Computers 

192 HONEYPOT LANE, QUEENSBURY. 

A?. JL*%. STANMORE, MIDDX HA7 1EE. 

a C jr6 

Tel:01-204 7525 


PERSONAL SHOPPERS WELCOME 
PHONE & MAIL ORDERS ACCEPTED 

ALL GOODSSCNT SA\1( DAY Y/HlACVCAFOSSIPLe 



«CL 

ICL brand Flexible Discs 
and Computer Tape are now 
available from Memorex. 
Ring the number on the dial 
below for IMMEDIATE 



: GO FORTH & * : 
FASTER DEVELOPMENT - 
FASTER PROGRAMS 


Laboratory Microsystems FORTHs - professional software complete with editors, 
assemblers, turn-key compilers, system utilities, multi tasking 8nd extensive documentation. 
* * * 68000 FORTH AVAILABLE NOW for CP/M 68K * * * 

Z80 C/PM 80. 8" £45, 5" £60 CP/M-86 £95 

IBM PC £95 Sirius/Victor £105 

PC-F0RTH + 32-bit FORTH £190 CP/M-86 FORTH + 32-bit £190 

CP/M-68K £190 Many other versions 

FLEX and SAGE users - we support you too. Ask for Apples, PETs — 


Nautilus Systems Cross-compilers - transport FORTH to different processors, generate 
secure code, generate ROMmable code, the complete development machine - and very, very 
fast. 


Prices from £230 for your first target. 

Target processors include: 8080, 8086/88, Z80, 6800, 6301/6801, 6809, 68000, 1802, 
Z8, 9900/99000, Z8000, LSI-11 

FORTH tapes BBC A/B with editor, assembler, graphics, toolkit 

£25 

Spectrum 48K with colour and sound 

£14.95 

Nascom 2 under NAS-SYS 3 

£22.50 

DIY FORTH kits 

Installation manual - How to do it, model, definitions, editor 

Source code listing for one processor - choose from 

6502, 6800, 6809, 8080, Z80, 8096/8088, 9900, 1802, 

£7 

68000, Z8000, VAX, Apple ] [, LSI-1 1 , Eclipse 

£7 

FORTH books - range includes: 

'Starting FORTH' by Brodie 

£16 

'Systems Guide to fig-FORTH' by Ting 

£26 

JUPITER ACE - now with FREE 1 6k RAM pack 

£78+ VAT -£89.70 



\ 


J ft 

Microprocessor Engineering Ltd 

21 Hanley Road Shirley 

Southampton SOI 5AP 

Tel: 0703 775482 

V 

J 


56 


• Circle No. 144 


• Circle No. 143 

PRACTICAL COMPUTING October 1983 




Special Advertisement Feature 



High speed shredding 

Computer printouts often contain the most sensitive 
information in any company, yet the sheer speed at 
which the output flows can be enough to make disposal a 
major problem. To cope with this the Rexel ambassador 
range offers specialist DP shredders from micro to 
mainframe user capacity. Up to ISO feet per minute of 
multi part sets can be destroyed. Why not get in touch, 
and PH forward all the details. 


426 on enquiry card 


Cut company phone costs 

Do your staff use the telephone efficiently? If you have a 
feeling that some of your company's hard earned cash is 
being unnecessary donated to British Telecom you 
should be talking to Callog. The Callog service provides 
a detailed analysis of outgoing calls and encourages good 
telephone 'habits 7 by pinpointing departmental costs. 
Indeed, the Callog service can immediately show you 
savings on telephone expenditure — savings that will far 
outweigh the small annual cost of the service itself . 1 have 
all the details, 

427 on enquiry card 




PAGE PLUS 
Computers 


COMPILED BY- 




65Shawley Way Epsom Downs 
Surrey KT18 5PD 07373 52031 



Electronic typewriters 
with the Xerox touch 

With the 600 Series Rank Xerox have 
produced five electronic typewriters 
offering a host of features to make typing 
faster and easier with less effort and 
impeccable results. The memory 
eliminates repetitive typing; self 
correction ends lengthy manual 
correcting and the Xerox touch of quality 
and features such as automatic 
emboldening, centring and underlining 
give extra authority to all your typing. 
Text editing models are available too. 
Whatever your needs, there’s one just 
right for you — contact me now. 

432 on enquiry card 



A fast and efficient 
mailing system 

If your computer can produce invoices in 
a matter of minutes it seems crazy to then 
spend hours mailing them by hand. The 
Neopcst System Five-2 from Roneo 
Alcatel is designed to fold, insert, seal and 
frank in a fraction of the time it takes 
manually. The 'system 7 can be controlled 
by a single operator saving many costly 
man-hours and its modular construction 
gives in he flexibility to match your needs 
exactly. If you’re interested in saving time 
and money circle this number today for 
more details, 

428 on enquiry card 


The Xerox 820 II 
micro-computer 

The Xerox 820 11 is the micro-computer 
which can really benefit your business. 
And it comes with a unique piece of extra 
software — Rank Xerox expertise. 
Expertise which will not only show you 
how to ensure you get the best possible 
out of the Xerox 820 II for your business; 
but even provides a telephone help-line to 
advise on using their specially tailored 
software programmes. Plus Rank Xerox 
have the engineers and the resources to 
provide on-site servicing — something 
few r other manufacturers offer. Contact 
me now for further information, 

429 on enquiry' card 



It takes less than 30 seconds to transmit an 
A4 page of information to any 
destination in the world using Kalle 
Infotec’s latest digital facsimile 
transceiver, the Infotec 6400. Similar in 
size to an office typewriter the 6400 
provides a range of big machine features 
including high resolution scanning and 
printing, sophisticated operator controls 
and a local log 7 for management 
accounting. Naturally compatibility with 
Group III and Group II is standard. Get 
the facts from Kalle Infotec, Circle this 
number now. 

430 on enquiry card 




Photocopies for less 
than a penny each 

Tbat 7 s the promise from Roneo with their 
high speed reduction copier. The Roneo 
Rapier 23QR gives low cost, edge-to-edge, 
crisp clean copies everytime. The machine 
copies up to A3 — single sheets, books, 
etc — onto any kind of plain paper, 
letterheads, labels and transparencies. 
The 23 OR is designed with a touch 
sensitive panel to give trouble free 
copying. Features Include reduction A3 
to A4, A4 to A 5, A3 to B4, B4 to A4 t 
automatic document feed and sorter with 
security key operation to prevent ‘use 
abuse 7 . Contact me for full details, 

431 on enquiry cord 


More than a word processor 

If you want a revolutionary word processor, look no 
further than the new Dictaphone 6000. It can handle 
words and numbers. It can edit, arrange, select, count, 
File, print and answer questions. But iris more than 
simpiy a word processor. It copes with a whole range of 
micro-computer facilities like data processing and can 
exchange information with other terminals and 
computers, even mainframes. And for less than the cost 
of a secretary you can Lease the Dictaphone 6000. Circle 
this number and they will prove it to you. 

433 on enquiry card 




Twinlock Multistor 

Ironically, the 'paperless office 7 always seems to end 
up producing more paper than it replaces, and finding 
space to store vital computer printouts and tape reels 
is often a headache. If the problem is a familiar one, 
Twiqlock’s Multistor could be the answer. Tape reels 
and printout binders are kept in order and easy 
expansion in any dimension allows you to expand the 
system as your needs grow. Yet it all costs less than the 
equivalent cupboard! Make sure you get the details — 
circle this number now. 

434 on enquiry card 


A cut above the rest . . . 


Continuous stationery can create as many problems 
as it solves, with paper-cutting bottlenecks holding up 
output. But according to Bell & Howell their 
Fimafold 1000 provides a low-cost solution for small 
or medium computer installations. The accent is on 
ease of use and maximum versatility, with electronic 
control systems keeping the operator fully informed 
and in complete control. Interested? Circle the 
number and I'll be happy to send you full details. 


435 on enquiry card 




Muitistrike printer ribbons 

The hidden costs in computing can soon mount up so 
we 7 re pleased to be able to tell you about a new range of 
economically-priced muitistrike printer ribbons from 
Melkron International. For those using an electronic 
typewriter/ printer such as the Olivetti ET Series or 
Silver-Reed EX5Q/55 or EXP550, Melkron has a new 
multistrike ribbon which gives approximately 150,000 
sharp impressions — double the yield of a similar 
singlestrike product. Let me put you in touch with your 
local Melkron dealer. 


436 on enquiry card 





SERVING THE BUSINESS WORLD 



BOS/SALES LEDGER 

Provides facilities to maintain customer 
accounts from entry of invoices, credit notes, 
paymentsand journals through to credit 
checking, production of statements and cash 
forecasting. Both balance forward and open 
item accounting are available. 


BOS/INVOICING 

Provides facilities to produce invoices and 
credit notes and sales analyses by customer 
product, territory and salesman. BOS.' 
Invoicing automatically maintains stock 
records and sales ledger accounts. BOS/ 
Invoicing requires BO S/Sales Ledger. 


BOS/PURCHASE LEDGER 

Provides facilities to maintain all aspects of a 
company's purchase ledger from the logging 
of transactions and the approval of payments, 
through to the calculation of discounts, 
scheduling of payments, printing of cheques 
and credit transfers and the maintenance of 
supplier details. 


BOS/INVENTORY CONTROL 

Provides facilities to maintain stock records, to 
record and control stock Issues and receipts, 
to check re-order levels and lead times and to 
provide total financial management of stock. 


BOS/NOMINAL LEDGER 

Provides facilities to maintain ail aspects of a 
company's accounts. BOS/Nominal Ledger 
accepts input directly or from BO S/Sales 
Ledger, BG S/Purchase Ledger or BOS./ Fixed 
Assets and produces profit and loss 
statements, trial balances, balance sheets and 
detailed schedules by company, department 
andaccounttype. 


BOS/PAYROLL 

Provides at! the facilities to produce payslips, 
credit transfers and management reports fora 
company payroll. BOS/Payroll fulfils all Inland 
Revenue requirements for the calculation of 
tax deductions, contracted-in and contracted- 
out National Insurance, and covers SSP 
reporting (UK). 


BOS/GRDER PROCESSING 

Handles all aspects of multi-warehouse sales 
order processing; back orders, forward 
orders, regular orders, picking lists, delivery 
notes and invoices. Order details per product 
and per client can be displayed on demand. 
BQS/Qrder Processing requires 80S/Sales 
Ledger and operates in conjunction with 
BOS/lnventory Control and BQS/Microsafes. 


BOS/FIXED ASSETS 

Maintains a complete register of the fixed 
assets of a company or group of companies, 
and calculates depreciation automatically 
either by historical cost or current cost 
conventions. Current cost accounting 
conforms to $ SAP 16 (UK), 


BOS Software’s extensive experience in international software satisfies the needs of our 
clients, not only in the UK, butthroughout the world. 


Choose BOS Business and Office Software and you will be buying not only 

the most comprehensive quality range of software available for the micro market, but also 

BOS Software’s five years of international experience. 


BOS Software is supplied in the UK by MPSL. 


For further details of BOS Software 
complete this coupon, clip to your 
business card or letterhead and return to 

MPSL, 


MPSL, 67-89 Saffron Hill, 

London EC1N8QU, England. 
Telephone: 01-831 8811 Telex; 22763 



BUSINESS OPERATING SOFTWARE 


Name 

Company 
Type of Computer 


pci m 


58 


• Circle No. 146 

PRACTICAL COMPUTING October 1983 



PC Bulletin: news 


WORDCRAFT SYSTEMS first 
developed its dongles for 
Commodore and, later, Sirius 
micros. Now it has a version 
for the IBM PC. It fits into the 
parallel printer port — pro- 
viding another port for your 
printer — and contains code 
without which your software 
will not run. On the good side, 
at least the system allows you to 
make security copies, 

PC dongles cost £15, which 
is somewhat more than the 
£2.50 for the Vic-20 version. 
The minimum order is 100 so 
you cannot get a sample from 
Mike Lake, Word craft 
Systems, Oak Lodge, Farley 
Road, Derby DEB 6BW, Tele- 
phone: (0332) 683892. B 


PC dongles 
from Wordcraft 



Maximum 
expansion 
from Legend 

LEGEND has introduced an 
expansion card which will 
support up to 768K of directly 
addressable dynamic RAM, in 
either 64K or 256K segments. 
The card maps round the 
address space are already used 
to provide the maximum pos- 
sible, 1Mbyte. 

Contact Legend Industries, 
2,220 Scott Lake Road, 
Pontiac, Mi 48054, Telephone: 
(313)674 0953. Q 


0.5 Mbyte 
going cheap 

encotel is now importing the 
Profit Systems RAM expan- 
sion card, which provides an 
extra 512K for £445. PC-DOS 
2,0 is included free. 

Contact Encotel Systems, 7 
Imperial Way, Croydon 
Airport Industrial Estate, 
Croydon, Surrey CR0 4RR, 
Telephone: 01-686 9687/8 0 

Addressbook 

DECISION TECHNOLOGY has 
adapted its well-known 


Addressbook program for the 
IBM PC, with an XT version to 
follow. It is said to be easy to 
use and costs only £90. A 
WordStar interface is provided 
for use with Mailmerge. 

Contact Decision Tech- 
nology, 7 St Johns Road, East 
Molesey, Surrey KT8 9JH. 
Telephone: 01-979 5533. fl 

Front end 
revelation 

revelation is the name of a 
Pick look-alike front end to 
PC-DOS, which Is useful if you 
have the PC linked to an IBM 
Series/ 1 super-mini running a 
full version of the Pick 
operating system. It turns the 
PC into a minicomputer 
terminal, with access to a wide 
range of software, while 
retaining the ability to run 
packages under MS-DOS. A 
new application generator, 
Appgen, can be run under Pick 
or under Unix, providing a 
bridge between the two 
systems. 

Contact Interactive Data 
Machines. Telephone: (0302) 
786677. 0 

Pearls 
of wisdom 

the SYSTEMS generator 
Personal Pearl has now been 
released in a version for the 
IBM PC. It not only runs under 
PC-DOS but also under 
CP/M-S6 and Concurrent 
CP/M, Pearl is a relational 
database that outputs ASCII 
files For use in word processing 
and links to the Supercalc 
spreadsheet package. It uses 



KPG Hardware House is the distributor of the IDE Associates 
range of PC disc sub -systems. Latest products are a 3.9in. 5Mbyte 
removable cartridge system. Either can be fitted into a standard 
PC in place of an existing floppy drive, or into an external 
expansion unit. Installation is said to take 15 minutes. Contact 
KPG Hardware House, 578-586 Chiswick High Road, London 
W4 5RP, Telephone: 01-995 3573. 0 


the IBM’s function keys, and 
costs £190. Contact Pearl 
Software, 12 Christchurch 
Road, Bournemouth BH1 
3LD, Telephone: (0202) 
20692/3. 

Graffcom has been rewriting 
its 8080/Z-80 machine-code 
packages in 8086/8 code to 
make full use of 16-bit CPUs. 
The new range, designated 
2020, includes word- 
processing, financial -planning 
and Configurable Manager 
packages. The series has just 
been implemented on the IBM 
PC. Contact: Graffcom 
Systems Ltd, 102 Portland 
Road, London Wll 4LX. 
Telephone: 01-385 9422. 

Micropro, the publisher of 
WordStar, now has all its 
software available on the PC. 
The latest offerings are 
CalcStar — improved to offer 

I, 300 cells — and InfoStar 

WordStar, SpellStar and 
Mailmerge are, of course, 
already familiar under PC- 
DOS. Contact Micropro 
International Ltd. Telephone: 
01-487 5728/9. 0 

The Strategist 

ASHTON TATE, author of dBase 

II, has launched a new finan- 

cial package called the Strat- 
egist. After you enter 31 key 
business assumptions, the 
program tells you if your prop- 
osed project will succeed or 
fail. The information is 
presented as 44 graphs and 
three detailed reports. Results 
can be sent along to dBase II. 
Contact Skye Quin at Ashton 
Tate (U.K.) Ltd. Telephone: 
(0908) 568866. 0 

Edison on PC 

THE Edison portable software 
system runs on a PDP-11/23 
minicomputer, and now also 
on the IBM PC with 256K of 
RAM. Edison is a Pascal -like 
language. 

The Edison system includes 
an operating system, compiler, 
screen editor, text formatter, 
print program and assembler. 
For more information read Per 
Brin eh Hansen/ s book 
Programming a Personal 
Computer , published by 
Prentice-Hall, 

Contact Per Brinch Hansen, 
Computer Science Depart- 
ment, University of Southern 
California, Los Angeles, Ca 
90089. 0 | 


PRACTICAL COMPUTING October 1983 


59 


IBM XT 

In the third part of our review, Jack Schofield looks at 
the operating system, which may not be so easy to get 
used to. The hard disc and PC-DOS version 2 demand 
a high level of literacy. 


IBM'S MAIN marketing thrust of the Per- 
sonal Computer has been at presenting it as 
user friendly. Indeed, the twin-floppy 
version is easy to use compared with most 
previous small business micros. This is due 
to PC-DOS, the IBM version of 
Microsoft's MS-DOS, and the high quality 
of much PC software. While PC-DOS is no 
one's Idea of the perfect operating system, 
it is easier to learn than CP/M. However, 
with the hard disc version of the IBM PC, 
the XT, and the essential PC-DOS version 2 
the system moves to a higher level of 
difficulty. 

There are several reasons for this. First, 
DOS 2 has more commands and is 
inherently more complex than DOS 1; it is 
not just bigger. Second, controlling the 
hard disc requires a much more organised 
approach to keeping files and back-ups. 
Third, very little current software has been 
written with hard disc operation in mind. 
The result is that the IBM XT is currently a 
much less viable option for the newcomer 
to computing. At the very least, the typical 
XT user will require a higher level of dealer 
support, and greater personal com- 
mittment. 


This is not because of the hard disc itself, 
which is big, fast and in principle works just 
like a floppy. It also takes up the same 
amount of room but it has two platters, 
giving four surfaces for data storage. Each 
surface has 306 tracks of 17 sectors, 
compared to 40 or 80 tracks on a single- or 
double-sided 5.25in. floppy. The total 
storage is thus about lOMbytes, which is 
the equivalent of 32 of the 320K standard 
floppy discs. Access time, the time to read 
an item of data, is up to 10 times quicker. 


IBM does not disclose the manufacturer 
of the fitted hard disc; likely sources are 
Seagate Technology of California and 
Miniscribe Corporation of Colorado. 
When the XT goes into production in 
Scotland in November there may be an 
opening for a Scottish disc. The disc in the 
XT supplied for review offered initial 
formatted storage of 10,592,256 bytes or 
1Q,344K. Even after copying on the DOS 2 
system files there w’as more than 10Mbyte 
free. Such information is very simple to 



60 


PRACTICAL COMPUTING October 1983 




discover using the ChkDsk utility from 
DOS, which lists hidden files like DOS. SYS 
and IO*SYS separately. 

The main new commands in DOS 2 are 
Assign, Backup, Break, Cls, Ctty, Echo, If, 
For, Shift, Goto, Graphics, Mkdir, Rmdir, 
Chdir, Path, Prompt, Recover, Restore, 
Set, Tree, Ver, Verify and Vol. There are 
four new characters, < » > , | and V Also 
some of the existing DOS commands have 
been enhanced, mainly to cater for hard 
disc operation. 

Backup has been added to allow the 
contents of the hard disc to be copied to 
floppy discs, since IBM do not have any 
kind of tape streamer or cartridge to do 
this* The simple command Backup C:\ 
A:/S backs up all the files on C, including 
those hidden in subdirectories. DOS makes 
a note in the directory whenever it writes to 
a file, so the \M parameter is provided to 
back up only those files which have been 
modified since the last back up was done, 
DOS also keeps time and date records, so 
the \D parameter is provided to back up 
only those files created after a certain date. 
That will make you wish you had entered 
the date every day when booting PC-DOS* 
In all cases, Restore is used to copy the files 
back onto the hard disc. In most other 
respects Backup seems to work like the 
usual Copy command. 

In general the new commands make 
using DOS 2 much more like using a 
language than using an operating system* 
The user is involved in numerous little bits 
of programming using Copy*Con, an 
abbreviation of copy from console, to 
create a file which sends commands just as 
though they had been typed in at the 
keyboard* Thus it is the equivalent of 
Submit in CP/M. Copy. Con is used to 
create Autoexec and other batch files which 
enable programs to be customised, so they 
can be run by inexperienced users. With the 
Echo Off command the process can be 
made invisible. Variables can be included 
using the % sign. Using Goto, For, To, and 
Cls to clear the screen, it is not unlike 
programming in Basic except that the 
system provides virtually no help with 
debugging. 

Most of the other new commands are 
connected with the provision of tree- 
structured files, through which DOS 2 is 
made to resemble Unix — specifically, the 
Microsoft version called Xenix. The idea is 
to divide the hard disc into a series of 
directories, created by typing Md or MkDir 
for Make Directory. This directory then 
contains files or sub-directories, which in 
turn contain files, and so on down through 
as many levels as you require. The only 
limitation is that the Path must not be more 
than 63 characters long* 

You start in the root directory but can 
change to a subdirectory by typing Cd or 
ChDir for change directory* Typing Dir at 
the root level lists only files in the root 
directory and sub -directories, which are 
identified by < DIR> * Typing Dir inside a 
sub-directory lists only files in that 


PCBulletin: review 


OCOPY CON: LOGON. BAT 

ECHO OFF 

CLS 

ECHO YOUR PASSWORD IS BEING CHECKED 

IF ■/.!=» JACK GOTO A 

ECHO ACCESS DENIED. GET LOST! 

ECHO OFF 
GOTO END 
: A 

ECHO PASS, FRIEND 
ECHO ENTER YOUR COMMAND 
ECHO A - WORD PROCESSING 
ECHO B - MULT I PLAN 
ECHO C * STRIP POKER 
SEND 

a z 

i File(s) copied 


Listing 1* A PC- DOS program which shows 
how you might write password system. 
Typing Logon Jack offers a election of 
programs in a menu, whereas Logon Fred 
results In a Get Lost message. With more 
users the variable %1 would have to be 
compared with other possible entries. 
Also, It would have to be an Autoexec. Bat 
file and not send unwanted users straight 
into the system at :Ertd, but this is just for 
Illustration. Note that three more files have 
to be created, A* Bat, B.Bat and C.Bat, to 
run the programs from the menu* Listing 2 
changes the directory to MPUACK and 
runs MuEtiPlarv MP. 

directory and the names of sub-sub- 
directories. The root directory is then 
effectively invisible to the system* The 
particular directories and files in use can be 
specified by the Path command. Thus it is 
simple to set up a password system where 
the password takes users only to their own 
set of files, so several different users could 
use the same machine. 

For example, the root directory could 
contain half a dozen *Bat files for main 
applications such as word processing, 
financial planning, etc* Selecting one from 
a list Echoed to the screen, then typing a 
name or password could take the user into a 
directory containing only their own files for 
(continued on next page j 


OCOPY CON: B.BAT 

CD\MP\X1 

PATH\MP 

CD 

MP 

y, Z 

1 Fi 1 e is) copi ed 


Listing 2. This routine changes the 
directory to MP/JACK and runs Multlplan, 


Specification 

SYSTEM 

CPU: Intel 8088 HMDS pseudo 16-bit 
running at 4*77MHz 
Memory: 128K of RAM expandable to 
640K; 40 K of ROM with socket for 
expansion to 48K 

Discs: single 5.25in. mini-floppy with 360K 
of formatted storage, plus 10Mbyte 
Winchester hard disc 
Features: 62-pin expansion slots for six 
full and two short expansion cards, but 
four slots are required to run basic 
system. 

Interfaces: cards for mono display/parallel 
printer and asynchronous 
communications supplied as standard 
Dimensions: 500mm. x 410mm. x 124mm. 

DISPLAY 

Type: 11.5ln, green phosphor screen with 
brightness and contrast controls 
Display: 25 lines by 80 characters 
Dimensions: 380mm. x 350mm. x 280mm.; 
7.9kg* weight 

KEYBOARD 

Type: two-tone Select ric-style qwerty with 
85 sculpted keys, including 10 function 
keys and 10-key cursor control/numeric 
keypad 

Features: Intel 8084 microprocessor 
control including 2K of ROM, 20-key buffer 
and n-key rollover; legs to provide tilt. 
Dimensions: 500mm* x 200mm. x 57mm.; 
2.8kg. weight, 

PRINTER 

Type* 80cps. graphics nine-pin dot-matrix 
printer, Epson MX-80, with parallel 
interface 

Features: tractor feed; range of print 
styles; stylish perspex stand is optional 
extra but recommended as it keeps the 
cables out of the paper feed 
Dimensions: 374mm. x 305mm* x 107mm.; 
5.5kg. weight 

SOURCE 

Manufacturer: IBM, available via dealer 
network 

Contact: IBM United Kingdom Ltd, North 
Harbour, Baltic House, Portsmouth 
P06 3AU 


PRACTICAL COMPUTING October 1983 


61 



PCBulletin: review 


{continued from previous page) 
that particular application. The Path 
structure might then be something like 
Path\MultipIan\Accourrts\Fred 
Fred would avoid all confusion with similar 
files created by Jim in Sales, whose 
directory would be found by 

Path\Mu!tJpian\Sales\Jim 

The program can even include If Exist, to 
see if a file or directory exists, and MkDir to 
create a sub-directory, for example, for a 
new user, if it does not. But this is not really 
a multi-user system nor multi-tasking, and 
would not meet any company's idea of 
security. The line “Echo Oh dear, someone 
erased your file’’ might well come in useful. 

Setting up the system obviously involves 
a lot of messing about with directories, but 
fortunately DOS 2 provides facilities to do 
this. For example, Dir | Sort will produce 
a directory which is sorted into alphabetical 
order. DirJSort > JimFiles will create a file 
called JimFiles and pipe the sorted listing to 
it. It can then be displayed on the screen 
using Type, or printed out. Numerical sorts 
can be done, and DirjSort/25 will sort files 
into chronological order, that is, by the 
25th column which holds the date. 

But operating DOS 2 is not all plain 
sailing, and the Path instruction proved to 
be a problem in practice; the system will 
operate happily inside a sub-directory, but 
will not fetch files from outside it. 
According to the manual, specifying a Path 
such as 

Path\Multiplan; \Multiplan\Jim; A; \Sales 
should send DOS to look in the current 
drive, C, then into the Multiplan 
subdirectory, then into Jim's Multiplan 
subdirectory, then to drive A, until it finds 
the file it is looking for. Whether 1 am 
misreading the manual or simply failing to 
observe the incredibly tortuous syntax 1 do 
not know, but I cannot make it work. 

When running commercial software the 
Path command seems to be totally ignored 


by DOS 2. Multiplan is one of the few 
programs that runs happily from the XT 
hard disc. The Trendtext/2 word processor 
gave problems by booting from C but then 
going to drive A for all subsequent files. 
The program as configured would not even 
accept C: as a drive identifier, so not even 
text files could be saved to the hard disc. 
TK! Solver, reviewed in our August issue, is 
copy -protected so it has to be run from 
floppy drive A anyway. However, it refuses 
to recognise the existence of drive C, no 
matter how configured. The only way 
round it is to Assign C to be B — no fun. 

Tomorrow's Office is supplied on six 
floppy discs which makes it a strong 
candidate for hard disc operation, other- 
wise you have to change discs the whole 
time; at its launch the program was 
demonstrated on the IBM XT. Again, 
however, the early review sample supplied 
proved impossible to configure for the XT 
in our office. Even when it could be 
instructed to look through C for files 
known to be on C, the program would hang 
up while waiting for the user to insert a disc 
in drive C* 

Inserting a floppy into the IBM hard disc 
is not a pastime to be encouraged, and 
Sosoft has responded with an improved 
version of the product to match the XT. 
However, not every company is likely to 
meet the challenge quickly, and not every 
software package will be easy to change. 
The Bristol Software Factory, producers of 
Silicon Office, has complained publicly 
about the situation. In the weekly trade 
publication Computing t August 4, Mike 
McDonald said he suspected there was a 
hardware difference in the interface with 
the machine's operating system which gave 
difficulties. 

So while some programs can be run from 
one drive some, like Context MBA, require 
two drives and cannot be run at all. In any 
event the most likely result s that the poor 


user who pays out a large amount of money 
for permanent ownership of an XT ends up 
with a single-floppy micro with a built-in 
10Mbyte back-up disc. 

Obviously this situation is going to 
change. IBM can currently sell XT's faster 
than they can make them and a queue is 
building up outside the sales department. 
The potential for software sales is immense, 
and the supply will arise to satisfy that 
demand. However, it does mean there is 
little benefit for the ordinary user in being 
near the head of the queue. 

In the long term the XT looks like a 
winner. The average small-business micro 
user will find that the ergonomic excellence 
of the IBM XT, the generous 256K of 
RAM, and the vast capacity of the hard 
disc a real boon. Switching from an 
ordinary eight-bit twin-floppy CP/M 
machine to the XT is like going from a 
Metro to a Mercedes. Both get you from A 
to B but there are differences in style, com- 
fort and convenience, as well as cost. 

It is a kind of comfort and convenience 
that most serious users plan to get used to. 
With the cost of hard discs dropping 
significantly at the moment, and with the 
mass of software and add-on accessories 
becoming available for the IBM, the XT 
version looks very much like being the 
Apple II of the next five years. It is hard to 
think of a higher compliment than that. 


Conclusions 

• The IBM XT with monochrome monitor 
and printer represents a well designed and 
well integrated system, which has great 
versatility and no obvious hugs. 
Ergonomically the system is outstanding, 

• The keyboard has an excellent touch, but 
the placing of four or five keys may create 
problems for some people. 

• Personal Computer DOS 2,0 is larger, 
more complex and more sophisticated than 
the previous versions. It is harder to learn, 
but the facilities offered will repay study. 
Many DOS 2 facilities are usable on twin- 
floppy machines as well as on the hard disc 
version reviewed, 

• DOS 2 offers a learning path and an 
upgrade path into Xenix, the Microsoft 
version of Unix. 

• Basics has been enhanced for the XT, 
and again the extra facilities are available to 
non-XT users* The language is not 
particularly fast or powerful, but contains 
an enormous number of commands. 

• The XT hard disc requires a lot of effort 
to organise, but after that should prove 
trouble free In operation. That there is no 
alternative to backing up onto floppy discs 
is to be regretted. 

• The system as reviewed, with 256K of 

RAM, graphics printer plus stand, and alt 
cards and cables costs £5,200 plus VAT 
from IBM Retail Centres. This makes it 
good but not exceptional value. However, 
as the price drops over the coming years the 
XT could well become the standard small- 
business micro* PJ 


Screen display which results from running the logon batch file. 

YOUR PASSWORD IS BEING CHECKED 
PASS, FRIEND 
ENTER YOUR COMMAND 
A ® WORD PROCESSING 
B = MULT I PLAN 
C * STRIP POKER 


OCHKDS K 
Vo 1 ume? JACK 


crested Jan I * i960 12s 04a 


Screen display from running the check disc utility for hard disc C. 

10592256 bytes total disk space 
28672 bytes in 3 hidden files 
4096 bytes in I . * di rector i es 
708603 bytes in 89 user files 
9850880 bytes available on disk 

262144 bytes total memory 
237328 bytes free 


62 


PRACTICAL COMPUTING October 1983 






WORLD'S FIRST 
INTELLIGENT 
ASCII KEYBOARD 


5(C Uses superfast 6800 D CPU 

# Uses the new revolutionary 7220 graphic chip 

^ Incredible 1024 x 1024 resolution in one plane 

GKS (graphic kernel system) supported 

5(Cy Usable either as stand alone or with another computer 
f (8255 interface chip) 

32K RAM/ROM (SK for system commands) 

1 2BK RAM for graphic, 16K for user program 
£699 + €10 P & P + VAT = £815 35 


True micropressor — based (uses 6809 CPU, 2K 
RAM and EPROM) 

5(C 111 (including 19 function keys and separate 

numeric and cursor pads) keys 
Ail function keys are freely programmable via 
"PROG 1 ' key 

^ Auto repeat on all keys (user selectable frequency) 
SfC Alpha lock, shift lock, MSB, 2 key rollover 


* 

* 

* 

* 


colour matches BBC micro 


height drives (57mm high) the case 
jfso accommodates slim line 14 height drives (41 mm high) - 

TWIN to track single sided 12Q0K) cased with professional grade switch mode PSU . . . E360 + £10 P & P + VAT * [425. 50 
TWIN $0 track double sided (4Q0KI eased with professional grade swflch mode PSU . , . [480 + £10PSPtVAT- £563,50 
TWIN 80 tra c k sided I8D0KI cased with profession^ grade switch PSU . . . E610 + E10 P & P + VAT - £713.00 


LED display of HEX values Mikrokey III 

Serial (selectable baud rates) or Parallel operation 
(please indicate choice) 

Roused in beautiful low profile two tone beige 
case (W528 mm, D T9B mm, H 57 mm) 

Comes complete with cable and connector 
£295 4- £5 P&P + VAT = £345 


only (without drive) 

£60 4- £5 P b P 4- VAT 
Slimline switch mode power supply 
used for 2 drives. 


CASE ONLY 

{Measures W 300mm x 0 350mm % H 57mm) 

£25 + E5P&P + VAT = £34.50 

(Please stale drive size - Vi (41mm high) nr % {57 mm high) 
height) 

SWITCH MODE POWER SUPPLY Suitable fpr TEAC, 
MITSUBISHI, CANON, BASF drives. 

Slim line (W 98mm x 0 200mm x H 45mm) + 5V @ 

3A, + 12V @ 2,5A fully regulated complete with cover 

£45 + £5 P 6 P + VAT = £57.50 

DISK FORMAT PROGRAM 

lor BBC micro £15 + £2 P 6 P + VAT = £19.55 

BARE DRIVES are also available at competitive prices. 

Please telephone lor derails. 


NEWFROM 

EPSON and RX80 







SWITCH MODE SLIMLINE 
POWER SUPPLY 


STARDP510 


LOW PROFILE 
PROFESSIONAL 
METAL CASE 
FOR 

COMPUTER 

SYSTEMS 


Model FX80 super 
fast dot matrix printer 

• 80, 137 column 

• 160 CPS print speed 
(100 CPS for RXB0) 

• 96 character ASC1 1 + 
up to 256 down-loadable 
user defined characters 


• Proportional spacing 

• Sub- script Super- script 

• Dot addressable graphics 

• Tractor and friction feed 
(Tractor only for RXEQ) 


FX80 £398 + £10 P & P + VAT = £469.20 

RX8D £298 + £10 P b P + VAT = £354.20 


* Centronics as standard 
(optional serial interface) 

* Auto underline 

* Vertical & horizontal tabs 

* Left and right margin set 

* Skip over perforation 

* Backspace 

* Self test 

* International characters 

* Serial interface £76 + VAT 


An astronomical array of features 
at a down-to-earth price. 

* 100 CPS bi-directional logic 
seeking 

* 9X9 matrix — true 
descenders 

* 2,3 K buffer as standard 


The oesi price/ pertormance printer only 
£298 + £10 p&P +VAT = £354,20 
(R8PE349 + VAT!) 

Star DP 510 — B0 column 


Friction, tractor, roll holder 
Hl-Res and block graphics 
Subscripts ( HzSOfl) and 
superscripts 
Italic printing 


■ 2 


Front 


houses Micronix 8DHO, Vi height 5'A Jf 
Floppies {Vi height floppies optional), a switch mode power 
supply for the complete system. The panels have cutouts for 
floppies, connectors and a fan (as illustrated). Thoughtfully " 
constructed for easy accessibility. Cover and base grey/ 
beige. Frame dark brown. 

Case fur % height floppies £90 + £1 0 P & P + VAT — £1 1 5 
Case for 14 height floppies £95 + £10 P & P + VAT = £120.75 




Measures only: 60mm H x 120mm W 

x 248mm O 

Input: 22 0/2 40V 50Hz 

Output: +5V @ 7 A; +12V @ 3A; 

— 5V @ 1A; —12V @ 1A; 
Enough power for Single Board Micro, 2 
Mini Floppies & CRT. 88 Watts. 

ONLY £77 + £3 P & P + VAT = £92 inc. 


micronix computers Ltd 

(formerly Vmcelord Ltd)* 1 

Suite 2, 26 Charing Cross Road, London WC2, TeL 01-240 0213/0217* Telex. 295173 VILORD G 


PRACTICAL COMPUTING October 1983 


• Circle No. 147 

63 









LOGICA 

VITESSE 

Chris Bidmead reviews a 16-bit micro from a leading 
U.K. manufacturer, which is also sold as a dedicated 
word processor and under the Merlin label by British 

Telecom. 


the yitesse from Logics is a good- 
looking relatively simple 8086 micro- 
computer that comes in a pleasantly 
designed cream box measuring 34cm. by 
46cm. and standing 25cm. high. This main 
unit holds the processing electronics and a 
pair of sensible capactiy 592K mini-floppy 
drives. The tillable screen and its keyboard 
are packaged as separate modules. 

The illuminated main power switch is on 
the front panel of the processor unit; after 
switching it on and waiting 10 seconds the 
screen comes alive with the single prompt 
Disk 

and a symbol of a rectangle and a back- 
ward-pointing arrow. The same symbol is 
used on the keyboard to idem if iy Carriage 
Return. With a system disc in drive i, 
hitting Carriage Return — or any other 
key — triggers the CP/M-86 boot 
sequence. There is no debugging PROM 
monitor below operating-system level. 

In most implementations of the eight- 
bit progenitor, CP/M-80, the operating 
system is small enough to fit on the outer- 
most track, track 0, of a floppy disc. The 
first few bytes of track 0 will be a very 
simple loader routine supplied by the 
hardware manufacturer to read in the rest 
of the system track and make sure it is 
placed correctly in RAM. 

CP/M-86 works in a very similar way, 
except that the operating system is too 
large to fit on a single track, and is there- 
fore represented by a file called 
CP/M.Sys. It still needs a loader on 
booting up, which is kept on track 0 as in 
the eight-bit version. ROM initiates the 
loader, the loader fetches CP/M.Sys and 


As far as I know all CP/M-86 implem- 
entations work like this /and MS-DOS is 
similar though its system software is split 
across several files. The working of the 
loader is worth mentioning, however, 
because one of my main criticisms of this 
machine centres around this point. 

The system disc supplied by Logica has 
only two files on it, CPM.Sys and a file 


called CPM.H86, which turns out to be a 
hex version of CPM.Sys. It serves no 
function, and I am baffled as to why 
Logica has included it and bothered to 
document its presence. It would be more 
helpful to have the rest of the standard 
CP/M utilities on the same disc, but for 
some reason they are supplied separately. 

The keyboard is uncramped, with 


Benchmarks 

Running the standard beehnmarks on the Logica under Microsoft Basic-86 revision 
5.22 revealed a relatively slow machlne 1 considering it uses an Intel 8086 
microprocessor like the speedy OEM Orion. 



1 

2 

3 

4 

5 

6 

7 

8 

Average 

Logics VTS 

1.8 

6.2 

13.0 

13.5 

15.5 

28.9 

44.9 

35.0 

19.85 

Zenith Z-110 

1*5 

5.1 

10.6 

11.0 

12.8 

24.3 

25,5 

28.5 

14.9 

\BU PC 

1.2 

4.8 

11.7 

12.2 

13,4 

23.3 

37,4 

36.9 

17.6 


64 


PRACTICAL COMPUTING October 1983 



Review 


height adjusters on the underside. The 
separate key clusters are well spaced out, 
and two shades of amber are used to 
differentiate the QWERTY keys from the 
function and numeric keys. Yet in practice 
the keyboard is less promising than it 
looks. Some crucial keys are in odd places: 
the Control key is on the right-hand side, 
the Backspace is on the left-hand side, and 
marked Erase Char, and there is a key 
called Back Tab where you would expect 
to find a Backslash. 

The top row of the QWERTY keys 
present a confused appearance, their tops 
being engraved with three characters 
rather than the usual two. On some of the 
keys the additional character is generated 
by holding down the Special key, but on 
others the connection between the key top 
and generated character appears to be 
arbitrary. The useful feature of Caps Lock 
is provided to hold alpha characters in 
upper case without shifting the other keys. 
It is a common enough feature on comp- 
uter keyboards, and is usually implem- 
ented on a single On-Latch/Off key. On 
the Vitesse you have to hold down Special 
and to set alpha lock and Special and 
to release it. 

Some of the keys carry mnemonics that 
are valid in the context of CP/M: Clear 
Cmd sends Control-Z to cancel the 
command line, Retyp Cmd sends Control- 
Re, Scrll On/Off sends Control-S. But 
many others are inscribed with names like 
Col Retrn, Mode Lock and Erase Word 
that bear no relation to the operating 
system or the software provided. 

The handily placed array of 12 function 
keys are unimplemented, beeping at you if 
you if you try to use them, and the cursor 
keys send out control codes that are 


Specification 

SYSTEM 

CPU: 8086 true 16-bit processor 

Memory: from 64K to 516K; review 
model had 256K 

Discs: twin 5.25in. 592K drives; 
literature suggests the intention to 
offer IMbyte drives 

Interfaces: Centronics; optional 
RS-232C 

Dimensions: 34cm. x 46cm. x 25cm. 

DISPLAY 

Type: 15in. orange phosphor 

Display: 24 lines x 80 characters with 
22 line option; seven-by-nine dot 
matrix, reverse video, bold, underline 

Dimensions: 35cm. x 37cm. x 38cm. 

KEYBOARD 

Type: detached, international standard 
full QWERTY pad 

Features: Calculator-style numeric 
keypad with 18 keys; 12 
programmable function keys, 
disabled 

Dimensions: 48cm. x 20cm. , height 
adjustable 

Manufacturer: Logica VTS Ltd, 86 
Newman Street, London W1A 4SE. 
Telephone: 01-637 5171. 

Price: £2,490 for 64K system 


echoed on the screen to no very good 
effect. This last point will come as no 
surprise to CP/M veterans but, with the 
IBM PC and so many other new-gener- 
ation machines offering cursor keys that 
remain meaningful at operating-system 
level, would-be customers are going to 
need some swift sales patter to smooth the 
rough edges. 

The large 15in. amber screen is stable, 
very easy to read and definitely the best 
feature of the hardware. It operates in two 
modes. One is plain and simple with 24 
lines by 80 columns while the other offers 
a message line at the top of the screen, 
reducing the work area to 22 lines by 80 
columns. 

The message line carries information 
about the status of the printer, the 
position of the cursor and — a useful 
touch this — translates the current I/O 
byte into the mnemonics used by Stat and 
Pip. Thus it keeps you permanently info- 
rmed about the logical-to-physical I/O 
linkages. 

Ideally the message line would be cont- 
rolled by dedicated hardware in the 
monitor, as with the more sophisticated 
serial terminals like the Cifer range, but on 
the Vitesse it is a software emulation. 
Switching it on, using the dedicated SCN 
Switch key, involves a warm boot of the 
operating system. If you hit this switch 
while inside an applications program to 
see whether the printer is ready, you will 
be disappointed to find yourself back at 
the CP/M command line. 

The review system arrived with discs for 
Micromodeller and Mars but no docu- 
mentation for these programs. Despite 
repeated promises that the manuals were 
on their way there was still no sign of them 
by press day. A more serious disap- 
pointment was the absence of Words- 
worth, Logica’s own word processor, 
scheduled as the main feature of this 
review but withdrawn by Logica at the last 
minute as not yet ready for exposure. 

Digital Research’s complete docum- 
entation for CP/M-86 was provided, 
along with provisional documentation for 
Microsoft’s MBasic. This language is now 
effectively unsupported under CP/M due 
to the internecine strife between the two 
operating-sytem vendors. 

One improvement CP/M-86 offers over 
CP/M-80 is the provision of a Help utility 
that explains how the various CP/M 
routines work. Logica salesman are going 
to have to do some more smooth talking to 
explain why Tod, the standard date and 
time utility documented within Help, is 
nowhere to be found on the utilities disc, 
Copydisk is explained there too: 

Copies all information on one disc to 

another disc, including the CP/M 

system tracks if they are present on the 

source disc . . . 

“System tracks” includes the vital loader 
on track 0 I mentioned earlier and that 
brings me to my main objection to 
Logica’s approach. 


Digital Research recognised very early 
on that, one valued aspect of the micro- 
computer, unlike the main-frame, was the 
user’s maximum independence from the 
manufacturer. In this spirit, CP/M 
routinely comes with a set of utilities to 
create new versions of the system on blank 
discs. One of these is Sysgen, the system- 
generation utility. Another standard way 
of creating new system discs is by using 
Copydisk, directly transferring all the 
tracks, including track 0, from one disc to 
another. 

As with Tod you will look in vain for 
Sysgen and Copydisk among the CP/M 
utilities offered with the Vitesse. Instead 
there is a utility called Backup, a track-to- 
track copier written by Logica that 
expressly omits transferring track 0. 
Logica is allowing you to create data discs 
and copy them, but has gone out of its way 
to make sure you will never be able to gen- 
erate new system discs. 

This is a mainframe marketing strategy 
designed to tie the user closely to the 
manufacturer. Readers of this magazine 
will have picked up the feel of the micro 
world enough to know that this is not what 
micros are about. I hope no amount of 
saleman’s rodomontade will persuade 
them otherwise. 

With such an extensive choice of dual- 
floppy micros available, customers can 
avoid this problem very simply. If they 
stay away from the Vitesse on this account 
Logica can hardly complain. The 
company might even be grateful — that 
way it can be absolutely sure nobody is 
copying its treasured system discs. 

Let’s hope Logica quickly changes its 
mind and falls in with the more neigh- 
bourly behaviour adopted by the majority 
of micro manufacturers. It would be a pity 
if such an amiable machine, with a large 
friendly screen and a fast, true 16-bit pro- 
cessor were given the cold shoulder on 
account of an old-fashion, misapplied 
marketing ploy. 


Conclusions 

• The Logica Vitesse has been developed 
from the company’s dedicated word- 
processor the VTS. The development is 
still in progress, and at the moment the 
system presents some rather ragged edges. 

• The hardware looks good and is 
pleasant to use. The screen in particular is 
large, with very legible orange characters. 

• The operating system is an incomplete 
version of CP/M-86, a historic piece of 
software that has not really seized the 
opportunities offered by the 16-bit 
environment. MS-DOS 2 and Concurrent 
CP/M have been available to OEMs since 
January. MS-DOS 2 would seem to be a 
natural choice, as Logica is the U.K. 
guardian of Microsoft’s Xenix. 

• Following in the leaden footsteps of 

Dec, Logica is apron-stringing its cust- 
omers by withholding the facilities for 
creating system discs. [T] 


PRACTICAL COMPUTING October 1983 


65 



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SINCLAIR ZX81 at£49.S 
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B&L Microcomputers 
announce their new 
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• Circle No. 149 


66 


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EPSON RX80-AMB 

EPSON FX80-- £340 
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• Circle No. 251 

PRACTICAL COMPUTING October 1983 

• Circle No. 150 ) 









1 983 

THE QUEEN S AWARD FOR 
TECHNOLOGICAL ACHIEVEMENT 


Technological 
Achievement in 
Office Automation 
Systems 

Logica VTS supplies word processing, 
personal computing, local area networking and 
multi-user office systems. 

■Word Processing 

Logica VTS is Britain’s largest manufacturer 
of Word Processors. 

■Personal Computing 
The ‘Vitesse 1 16-bit Personal Computer was 
selected by CCTA for Central Government 
Departments. 

■Office Systems 

Multi-function office workstations linked by 
high speed Local Area Networks. 

Logica VTS is already developing the office 
automation products for the next decade. 

If you require further information, contact: 

Marketing Manager, 


Logica VTS Limited, 

86, Newman Street, 
London W1A 4SE 
Telephone 01 637 5171 



Telex: 27200 



Acorn’s long awaited Electron is here. It is smaller and 
cheaper than the BBC Micros, but the machines have a 
lot in common. Neville Maude thinks it should do well. 



A Welcome tape is provided which 
follows the BBC Micro style. It includes 
Polygon; Island, where the waves move; 
and Draw, the horizontals and verticals 
are fine, diagonals difficult, and curves 
almost impossible. 


Specification 

CPU: 65G2A running at 2MHz 
Memory: two 16K ROM/EPRGM chips 
plus 32K of RAM from four chips 
Keyboard: 56 typewriter keys in QWERTY 
layout 

Ports: UHF TV, video, RGB monitor and 
cassette ports; expansion bus 
Features: colour graphics and sound; 
number keys used as function keys; 
optional single-key Basic keyword 
entry; user-definable characters 
Notable ommissions: BBC Mode 7; no 
joystick ports 

Power supply: separate, 19V 14W 
Dimension: 343mm. x 159mm. x 57mm, 
Origin: assembled in Malaysia for Acorn 
Computers, Fulbourn Road, Cherry 
Hinton, Cambridge CB1 4JN 
Price: £199 



Technical details 

The 6502A processor runs at 2MHz when 
accessing ROM, but in the Electron at 
1 MHz from RAM. This is because the 
RAM is in four 64K by 1 -bit chips, for 
cheapness, so every access needs two 
operations. 

In modes 0,1 and 2 the RAM access of 
the video part of the ULA is interleaved 
between the 6502 A access. For 40^s out 
of 64 the processor is out of action. In 
mode 3 the processor is running full 
speed on alternate lines. In modes 4, 5, 
and 6 it runs at 1MHz all the time it 
accesses RAM. Hence a program taking 
10 seconds on the BBC in all modes can 
take on the Electron about 43secs in 
modes 0,1, and 2, about 34secs in mode 
3, and 20secs in modes 4,5 and 6. 

A trick is to draw graphics by shifting 
the Electron into its faster modes during 
the drawing period and then back again. 
The screen display will be somewhat 
strange during that period but become 
normal at the end. 

The ULA register of mode is in &FE07, 
a write-only register, and the operating 
system uses &0283. So program inserts 
could be something tike: 

500 DEFPROCquick 
510 7&FEQ7 s &B0 
520 ENDPROC 

(PROGRAM) 

900 DEFPROCsJow 
910 7&DE07 = ?&0282 
920 END PROG 

Of course, this does not help to speed 
up programs where the graphic display 
is used not just drawn, but it helps with 
those like Persian, In both manuals, 
where one locks at the results. Times for 
this are about 34secs on the BBC, 

SOsecs with Procquick on the Electron or 
105secs unaided. 


68 


PRACTICAL COMPUTING October T 983 









Review 


the electron is small, neat — less than half 
the size of its ancestral BBC Micros. The 
finish, including keys, is light cream and 
mainly plastic which contributes to its light 
weight. 

The mains transformer, 19V 14W, is 
separate and has an integral three-pin plug, 
which is rather large, 3.5in. by 2.5in. by 
2.65in., excluding prongs. This can cause 
problems with some switched sockets or 
double sockets when two plugs are being 
used. The advantage of having only low 
voltage reaching the computer is obvious, 
especially for children, there is also no 
heating problem in the main casing. The 
transformer appears to have a thermal 
overload cut-out — a good idea. 

The nominal RAM is 32K, which is not 
immediately apparent from the instruction 
books. If one asks the computer now much 
RAM is spare, with the standard phrase 
DIM P%:PRINT HIMEM - P% 
the answer is 20,990. It is because the 
Electron does not support the teletext mode 
7. The nearest is mode 6, see table, which 
needs about 8K as compared with mode 7 


which uses IK. Apart from this ommission 
the modes are the same as for the Model B, 
not the A — a real achievement in so low- 
priced a micro. The high-definition modes 
0,1, and 2 need 20K as they do with Model 
B but this is unavoidable, for example, 
mode 5 permits 16 colours with 160 by 256 
pixels. In general the graphics are 
outstandingly good though slower than the 
Model B. 

The standard question to determine the 
operating system with these micros is *Help 
and the Electron replies with 1.0 OS, not 
the latest 1.2. However, it is versatile with 
plenty of *FX commands. Indeed, there are 
a couple which the Model B does not have, 
namely *FX226 which sets the base number 
for Func A to P, and *FX227 which does 
the same for Func Q to /. 

There are four sockets on the left of the 
computer, not the right as shown in the 
manual, and these are labelled underneath 
the case, UHF TV, video, RGB, cassette. 
The video socket is for a monochrome 
monitor and the DIN socket for the cassette 
player is for 1,200 baud, not alterable to 


300 baud. There is also a multi-pin 
connector under the body, thoughtfully 
shielded with plastic in case anyone puts the 
micro on a metal projection. Presumably 
this will be used in conjunction with the 
first add-on for the Electron which is called 
the Elk. It is a general-purpose module to 
enable sideways ROMs, printer interface, 
games paddle sockets and RS-232. 

The ULA is a large one, about 30mm. by 
30mm. with 68 connections. It controls the 
colour palette and takes over the CRT 
controller action of the 6845 in the Model 
B. 

But the Electron has no 6845, so there 
can be no sidways scrolling as used in games 
such as Planetoid. Internal timing is also 
taken over by the ULA, as is sound. This is 
less complicated than the BBC method. To 
allow reasonable compatibility between the 
two micros there are three tone channels 
and one for noise. However, only one tone 
channel at a time can be used on the 
Electron and the envelope is also more 
simple, most people will find it still complex 
enough. 

If tested for speed using the statutary 
benchmarks the Electron runs about 30 
to 40 percent slower. Arithmetical 
computations are the slowest but, since the 
BBC Basic is so fast the Electron is still 
doing well. 

If one tries to load a BBC cassette into 
the Electron the the title page usually comes 
out as monochrome hash — not always. 
The main program generally loads but then 
runs like an arthritic snail, about 2.0 to 4.3 
times slower than it should. The Electron 
does its best, for example, it interprets 
mode 7 as mode 6 instead of just stopping, 
and since it cannot implement the double- 
height BBC command for titles it just prints 
two identical normal-height lines. The 
programs on the Electron Welcome tape 
ran perfectly on the Model B, but at present 
it is not known if the versions of Snapper, 
etc., being rewritten for the Electron will 
be perfectly compatible on the Model B. As 
a very rough rule, programs for the BBC 
Micros will not work on the Electron unless 
altered; programs for the Electron 
probably will work on the BBC but may not 
take advantage of all BBC facilities. 

The Electron keyboard is a real one, not 
rubberised plastic, an experienced typist 
reported that she was perfectly happy with 
it. The construction is a little cheaper than 
that of the Model B but is still good. The 
number of keys has been reduced and both 
the user-programmable keys and the cursor 
keys are combined with others. A function 
key may be used in conjunction with 29 
keys to give Basic keywords. For example. 
Print may be entered in full or as P or Func 
P, so the Electron has the best of both 
worlds. There are two ommissions, Tab 
and the shift lock, but those who never had 
them will presumably not miss them. 

In general the Electron keyboard is easier 
to learn than the BBC and considerable 
thought has gone into making it simple. 

(continued on next page) 


Mode 

Characters 

Pixels 

Colour 

Memory 

0 

80x32 

640 x 256 

2 

20K 

1 

40x32 

320x256 

4 

20K 

2 

20x32 

160x256 

16 

20K 

3 

80x25 

TEXT 

2 

16K 

4 

40x32 

320 x 256 

2 

10K 

5 

20x32 

160x256 

4 

10K 

6 

40x25 

TEXT 

2 

8K 



The ULA is a major reason for the Electron being cheaper than the BBC computers. 


PRACTICAL COMPUTING October 1983 


69 



Review 


ELECTRON 

(continued from previous page) 

The programmable keys run from 1 to 9 
and then 0, as distinct from the BBC 0 to 9 
series. The change means that the numeric 
and f values are the same on the same keys. 
Only one definition can be put in each 
programmable key, not three as in old 
BBC. Small hands will find it easier to 
reach keys without stretching, a useful 
point since most Electron users will be 
young. 

The Electron comes with a user guide, 
290 pages, in a ring binder. It is smaller 
than the BBC one, partly because there is 
less to descibe but also because it is written 
more simply. Apart from not having an 
index it is a really superb book with better 
organised information than in the more 
detailed BBC manual. Those who have 
trouble with the BBC could try this volume 
as an alternative, if available separately, 
since much of the information is similar. 

Another book supplied is Start 
Programming with the Electron; again this 
is excellent, much better than most other 
books written to help learning to program 
the BBC computer. One hopes the authors 
will produce a companion book for the 
BBC, otherwise this one will help to get 
started with both. 

A Welcome tape is provided which 
follows the successful pattern with small 


improvements from experience. Some 
programs, such as Patterns, are much the 
same. Gomuku has come in from the BBC 
games of strategy cassette, Island is from 
Aeornsoft’s graphics book and others are 
new. A two metre coaxial lead is provided 
for connection with a television set, 
production machines will also have a lead 
for the cassette player. 

Many comparisons have been made 
between the Electron and the BBC micro; 
unavoidable as the latter is a known 
machine and the two have so much in 
common. Nevertheless, in the market place 
the contest will be between the Electron and 
micros costing less than £200 — a crowded 
arena. The Electron should do well as it has 
many advantages over the present 
competition. Others will arrive, in 
particular there are Ataris on the way; the 
600XL and 800XL should come in this 
price range and are said to be compatible 
with the vast range of existing software. It 
is not impossible for Acorn to reduce its 
price should it become necessary. Acorn’s 
decision not to release machines to software 
houses prior to the launch is interesting. On 
one hand it gives Acorn about two months 
lead with its 10 or so cassettes which are the 
first to be converted, on the other hand 
software sells computers. 

The Electron will go out to dealers and 
high street chains. Acorn projects sales of 
100,000 by Christmas with W H Smith 
stocking it and then perhaps Boots. The 


Electron should carry BBC Basic into many 
more homes and it is anticipated children 
will use the BBC at school and the Electron 
at home. Curry is quoted as saying "The 
BBC is happy because they see it as support 
for the language, making it as standard as 
possible.” 


Conclusions 

• The Electron is an excellent micro for the 
money, it is rumoured it will sell for £199. 
It is a little unfair to compare it with the 
Model B which costs more than twice as 
much. 

• The Electron will sell well at the cheaper 
end of the market place and the first add-on 
module should be available almost 
immediately after the launch. 

• The Electron is not a replacement for the 
Model A; the Electron cannot he upgraded 
to a Model B, as could the A, Even w hen all 
add-ons are available, which will make the 
cost higher than a Model B, the result will 
still be an augmented Electron, not a B, 

• Backing will be good; books for the 
Electron have been written and a users club 
has been announced. 

• The Electron has a good keyboard, 

colour, graphics and Basic plus strong 
connections in the educational field. It can 
be recommended as a first computer on 
which to learn, or as a step up from still 
cheaper types such as the ZX-81. Q 





Up to scratch? 


Genuine computer specialists can always come up with the 
answer. So if you’re puzzling about which computer would suit 
your purpose best, don't worry any more. Just come along to the 
Leeds Computer Centre. We ’ll be delighted to advise and 
demonstrate from our stock which covers the whole international 
computer scene, vyith an emphasis on quality and value. This 
isn 't the sum total of what we can do to help you. Perhaps you 
could use advice on extending your present system. Or would 
you like to attend our seminars or have employees come along ? 

The Leeds Computer Centre is equipped with computers and 
all that goes with them, particularly expertise, to solve your 
particular problem(s). 

All you have to do is ask, preferably in person or initially by 
telephone. 

Main dealers for:- 

Sharp, Epson, Gemini, Quantum, Nascom & Dragon 




lEns'slecPi 

COMPUTER PRODUCTS LTD, 


55 Wade Lane , 

Merrion Centre T Leeds 
LS2 8NJ Tel (0532) 458877 


70 


• Circle No. 124 

PRACTICAL COMPUTING October 1983 




SYMBIOTIC 

COMPUTER SYSTEMS LIMITED 



SYMBFILE SYMBSTORE 

v r wixcm-STKRsi h system TAPE STREAMING; BACK UP 


- SYMBFILE hard disk subsystem is a complete add-on mass storage 
tern for the Apple |[. ]| + . |[E, or /// microcomputers and is at present 
ng developed for the SIRIUS, IBM PC and the BBC micro. It is 
npatiblc with the majority of hardware products currently available 
the Apple, including the 16K Language card and 80-column cards. 
MBFILES are available in sizes from 5-21 megabytes, 
ull DOS, Pascal, and CP/M support allows any standard application 
ware, including database, word processing, and accounting 
kages to be used. 


SYMBSTORE is the perfect complement to SYMBFILE giving a high 
speed, totally reliable back up system. SYMBSTORE will copy the 
entire contents of a SYMBFILE to a C60 type digital cassette. 
SYMBSTORE'S unique multiple buffer verification ensures the perfect 
transfer of data. Software to individually back up volumes and files 
under present operating systems will soon be available on request. 



SYMBNET 


LOCAL AREA NF.TWOKK 


SYMBPLEXER 

XKTU’OKK COXTROl.l.RR 



SB?--..- 


k/IBNET is a ‘‘tree and branch'’ network system using fibre optic cable 
illow several microcomputers to share a common SYMBFILE. 
/IBNET is the fastest long range local area network for 
^computers, and can cover a range of 7-9 Kilometres. Fibre optics 
ns that SYMBNET is more cost effective; it uses a high intensity semi- 
Juctor laser to transmit data and cables can be laid along the shortest 
e. whereas other networking systems use flat ribbon or coaxial cable 
:h are sensitive to electrical noise from fluorescent lights, 
tocopiers, etc. SYMBNET is compatible with DOS, Pascal, SOS^and 
VI running on any microcomputer supported by the SYMBFILE in 
:urrent operation. 


The SYMBPLEXER is a network controller which complements 
SYMBNET. The SYMBPLEXER is connected directly to the SYMBFILE 
and performs all read-write operations to and from the hard disk. 
SYMBPLEXER does away with the need for a central machine thus 
releasing another terminal to run any application you wish, being a 
dedicated device the read-write operations are performed very 
efficiently, the support software allows SYMBPLEXER to designate 
pass codes for each user and to decide which user may access which 
applications. If you are currently using SYMBNET , accessing your 
SYMBFILE via a central machine, the addition of a SYMBPLEXER will 
in no way change the operational capabilities of the network. 


For more details of all SYMBIOTIC products contact 


SYMBIOTIC 

COMIMTKK SYSTEMS LIMITED 

Duroma House, 32, Elmwood Road, Croydon, Surrey CR9 2TX ® 01 683 1 137 PBX Telex 893815 









Inside the 

Advance 

An IBM look-alike for the price of a BBC — sounds too 
good to be true. Ian Stobie went along to check it out. 



a 16 -bit machine built around the advanced 
8086 processor with I28K of RAM and a 
modeiT^wsiness saandaod 
£350 lodel 

B. disc -based system 

wit^twy*ro rives with WordStar, Mai I merge 
uijI^alcStar thrown in, for £1,200, These 
two systems from the North London-based 
company Advance Technology ILK. 
certainly have remarkable specifications 
for their price. 

Both models, the Advance 86 Model A 
and the Advance 86 Model B, are scheduled 
to be launched in September. 1 had a look 
at pre-production versions and talked to 
some of the people behind the systems. 
What I actually saw was the electronics of 
the systems without production casing, and 
pre-production mock-ups of the casing the 
systems will be delivered in. Advance say 
September is when it hopes to be actually 
delivering systems to computer shops. 

Externally the Advance looks like a 
modern business computer. The Model A 
comes in two units, a system box and a 
separate detached keyboard on t he end of a 
cable. The Model B comes in a third box 
containing two disc chives and other 
goodies. This clips on top of the Model A 
system unit. So really there is no separate 
Model B, but rather an expansion unit 
which converts the Model A into a Model 
B. Model A users can convert to the disc- 
based system for £852. 

The reason there are two models is to 
enable the Advance to address two distinct 
market slots. The model A is aimed at the 
kind of people who are buying the 
Com m o d ore 64 and B B C com p u t ers . 

The disc-based Model B is aimed at the 
same kind of people as the IBM PC itself, 
or people who are buying IBM look-alikes, 
or even eight -bit business systems like the 
Osborne which have some application 
software thrown in. 

The Advance keyboard would certainly 
impress most home micro users. It is 
deliberately very like the I BM PC in layout, 
but to my mind there are certain 
improvements. The left Shift key has been 
moved to a more normal location next to 
the Z key, the Return key enlarged, the 
numeric keypad moved slightly to the right 
to separate it from the main keyboard. 

The system box contains the main board 
with its 8086 processor and 128K of RAM. 
The box is large and flat and, in the mock 
up at least, is chocolate coloured. Looking 
at the electronics which goes in it, it could 
have been much smaller, but since the idea 
is to have the Model B expansion unit sit on 
top it makes sense to have both boxes the 
same size. When not in use the keyboard 
can be stored away inside the system unit, 
so the Advance will not take up too much 
I space on a desktop. 

Even the entry level Advance Model A at 
£347.82, comes with I28K of RAM and this 
can be expanded on board to 256K. By 
home micro standards this is enormous. A 
further 16K of RAM is set aside for the 
display. The system can put out 25 lines of 


There is no separate Model B, an expansion 

text in either 40- or 80-column widths, or do 
high -resolution gralhcs in up to 16 
colours. No display device comes with the 
system but three different outputs are 
provided, for domestic TV, RGB monitor 
or composite synch, monitor. A cassette 
port is provided so programs and data can 
be stored using an ordinary domestic 
cassette recorder. The system comes with a 
joystick port and a Cemronics-type 
parallel-printer port filled as standard. The 
printer port in particular is worth having as 
connecting a printer to systems like the 
Commodore 64 or Atari can involve 
appreciable extra cost. 

The Model A will run cassette- based 
commercial software; Advance say they 
will be marketing a range of titles. In the 
United Stales though not in Europe an 
entry level cassette-based version of the 
IBM PC has been available, so there is 
some American software which should run 
on the 86 Model A. Advance say that with 
1 28K of memory available It is possible for 


unit converts the Model A into a Model B, 

software suppliers to easily adapt many 
disc-based packages for distribution on 
tape; this obviously applies to programs 
which do not make disc accesses when 
running but are simply quite large. 

The Advance’s third unit, the Model B 
expansion unit, clips on lop of the main 
unit. It is quite simple to fix and no external 
cables are involved. Once clipped together 
the two boxes are meant to be treated as 
one. The expansion unit contains another 
circuit board and two Shugart 5.25in. 
Hoppv drives, providing 640K of disc 
storage. The Advance’s 8086 processor is 
capable of directly addressing l Mbyte of 
memory, and with ihe Model B expansion 
unit RAM memory can be expanded up to 
768K. 

The Advance 86 Model B comes with the 
MS-DOS operating system, Microsoft GW 
Basic, an assembler, and three popular 
Micropro packages — WordStar, 
Mailmerge, and the CalcStar spreadsheet 
program. WordStar is the new version 3 


72 


PRACTICAL COMPUTING October 1983 


ELECTRONIC MAI£-IN M ICROSECONDS 

You could also link up with other Commodore 64s: 
in branch offices, for example, or in colleagues' homes 
with instant exchange of information. 

You could also plug in to half a million pages of 
cstel information, making use of key figures in 
combination with your own calculations for such 
statistics as you might need; or for other business uses, 
like car hire and hotel bookings. 

The Commodore 64 means maximum flexibility, 



tome office 


and provides the facts on which you can base sound 
business decisions. 


INVALUABLE TO ANY BUS I NESS 

The Commodore 64 is the perfect computer for 
your own business, whatever its size, As well as the 
advantages we've already mentioned, it has a great 
capacity for expansion, and when combined with 
various peripherals" it is superbly flexible. Whether it's 
looking after personnel records or creating models, say, 
for sales forecasts, it will quickly prove to be of vital 
importance to any well lun concern. 

MO RE POWER TO THE STt JDENTS 

A Commodore 64 in education puts more 
computer power at students' disposal. Subjects include 
maths, from basic arithmetic to higher functions; 
vocabulary building; elementary science; basic 
geography and of course, learning computing. 


FOR EVER YONE W HO HAS A H OBBY 



Apart from being an absorbing and fascinating 
pastime in itself, the Commodore 64 can be a tremen- 
dous help in countless hobbies. It's equally happy 
collating recipes for a cook or choosing moves for a 
chess enthusiast. 

In short, the Commodore 64 is one of the most 
outstanding microcomputers ever built. Outperform- 
ing all other computers in its class (some at twice 
the price), it's the ideal business partner. 

And just as at home, at 


from Commodore. 

64K memory for £299’Of its kind, unbeatable, 
t its nrice. almost unbelievable. 



For more information on the powerful new Commodore 64, and 
the address of your nearest dealer, telephone or write to us at: 

The Commodore Information Centre, 675 Ajax Avenue, Slough, 
Berkshire, SL1 4BG. Telephone: Slough (0753) 79292. 

□ Business Enquiry □ Personal Enquiry 
NAME (MR/MRS/MISS) 

POSITION 


COM PANY 

ADDRESS 


S3 

o 

CQ 


POSTCODE TEL 


*LXC VAT - DETAILS CORRECT A T TIMEOFCOINO TO lUESS 
** most. ILLLfS I RAirn HERE ARE THE E >JSk HRIVE AN! 1 1 M > I MAT RIX HUNTER OTHERS 1NCLU1 >E A CASSETTE 
1 1KI VE. lOYSTICKV 3'AL H LIES,. I'RIK 'ItLU'LO fTltt MUCH NK (RE 

N li MACH INE ANI T SOT TWAKE SUHIECT Tf 1 AVA] LAW LI TV • C I fCl 6 N O 152 





TRIUMPH ADLER 

makes it all , 
refreshingly simple 


with the arrival of the 
8/16 bit Alphatronic micro 


The Alphatronic P3 micro: the latest, most powerful addition 
to the outstandingly successful Alphatronic family. An addition 
that makes Alphatronic the largest range of ‘ready to use’ 
micros on the market, priced from £1,895 to £2,345. 

The dual purpose 8/16 bit processor means you can 
make use of the wealth of proven 8 bit software now. As 16 bit 
software becomes more widely available, we can upgrade your 
P3 to 16 bit operation. 

The P3 is a micro version of a larger system - rather than 
a ‘blown -up’ hobby computer. It’s a high quality, engineered 
computer, designed to cope easily in the business environment. 

Triumph Adler is a world leader in business products 
and committed to simplifying business procedures and 
reducing business costs. We provide a helping hand to our 
customers and our dealers. With over 80 years’ experience in 
the business market our single source philosophy is second 


to none. We actually do what everyone else claims. We test 
software, educate your staff, supply high quality stationery 
and supplies and ensure your system runs smoothly. 

I n short, we at Triumph Adler are dedicated to making 
your life refreshingly simple and to providing successful 
computing for your future. 

To get the full story, simply clip your letterhead or 
business card to the coupon, or ring the Triumph Adler hotline 
on 01-250 1 71 7 and ask for department M MD. 


TRIUMPH ADLER 


Triumph Adler (U.K.) Umited, 27 Goswell Road, London, EC1M 7AJ.Tel. 01-250 1717 Am.mb.,,„ih.vo.,. w „o,o,* 


Please tell me in simple terms the benefits I can expect from the most extensive range of business micros. 

Name Company 

Address Telephone . 


1 Circle No. 153 






Rarclaycard & Access accepted bill 
subject to a 5% surcharge Payment 
welcome by cash, bank draft, 
Building Society cheque. Please 
allow 7 days lor cheque clearance. 
Instant credit available shortly. 


tipple 


Apple He 64k computer 

■only £ 645 * + VAT 


Immediate Delivery! ! 


Save ait extra £39.00 
by buying a bundle comprising: 
Apple He 64k 
Disk Drive with controller 
SO Column Card 
12" Green Screen Monitor 

Bundle price only 

£999*»vat 

'(When purchased with 
a part-exchange) 


Disk Drive with Controller £270 
Disk Drive without Controller £199 
12" Green Screen Monitor £99 

Apple 1 1 1 Mon itor with Stand £ 1 25 


Apple III 

Apple 1 1 1 256k wi lit monitor £2099 
Profile (5Mb 1 lard Disk) £ 1 495 
Additional Disk Drive ( 143K) £270 
I Parallel Interface £ 1 29 

OEM Prototyp ing Board £32 

Vinyl Carrying Case £49 


Software (Apple III) 


VisicalcIH 

£169 

Mail List Manager 

£99 

System Software (SOS) 

£175 

Quiekiile III 

£60 

Apple writer HI 

£133 

Business Graphics III 

£105 

Access III 

£89 

Catalyst 

£128 

Script III 

£75 

Other Software prices on 

application 


Software (Apple He) 

Vis i calc 

£145 

Visitrend Plot 3.3 

£182 

Multiplan 

£160 

Apple writer He 

£105 

Business Graphics 

£109 

Quickftlelle 

£60 

Senior Analyst 

£145 

A PM 

£137 

Apple Plot 

£38 

Pascal 

£149 

Pilot 

£69 

Fortran » * 

- *£112 

Ix>go 

£122 

Super Pilot 

£129 

Wordstar 

£230 

' Mail merge 

£130 

Word Handler 

£98 

Visischedule 

£180 

Other Software prices on 

application 


Operating Systems & Display 

Z80 Microsoft Card 

£215 

Z80 Microsoit Card (He) 

£325 

ZSODigttek Card 

'£145 

Videx 80 Col System 

£189 

40 80 Column Switch 

£25 

80 Column 64 K 


Expander Card 

£149 

Prototype/ Hobby Card 

£12 

IEEE 488 Card 

£235 

TV Modulator 

£14 


Epson Printers 


mm 

£279 

FX80 

£379 

MX100F T Type 3 

£420 

FX80 Tractor Feed 

£35 

IEEE Adaptor Board 

£65 

Serial Adaptor Board 

£65 


Sirius 

Sirius equipment is available within 
48 hours at unprintable prices. 
Please ’phone for details. 


Accessories 


Numeric Keypad 

£78 

Paddles 

£20 

Joystick 

£34 

Cooling Fan 

£45 

Voltage Stabiliser 

£230 

Acoustic Coupler 

£200 

10 Floppy Disks 

£20 

Listing Paper 9" 

£20 

Listing Paper 16 " 

£29 

Monitor Stand 

£18 

Vinyl Carrying Case 

£17 


Other Printers 

Apple dot Matrix 

£349 

Apple Daisywheel 

£1150 

TEC40cps Daisywheel 

TEC 55cps Daisywheel 

£1095 

£1295 

■ Other Printer prices 
1 on application 



1 Apple H Accessories 

Integer Card 

£99 

Euro colour Card 

£73 

language Card 

£106 

Paddles 

£20 

Joystick 

£26 

Numeric Keypad 

£78 


APPLE 

He 

£645 


HOME 

COMPUTERS 

at 

GREAT PRICES 


VISA 

" . ■ 


Interfaces 
Serial Printer Card 
Parallel Printer Card 
Wizard 16K RuJlered I, F 
Wizard 16Kio32K Upgrade 
Thunder Clock 
8 Channel A/ D Converter 
Grappler 


Immediate Delivery 


(+VAT) 


Software (Apple II) 


Applewriter 1 . 1 

£39 

Apple Plot 

£38 

Applewriter 2 

£89 

Circuit Analysis 

£23 

Apple Super Pilot 

£129 

DOS Tool Kit 

£41 


Export Orders Welcome!!! 


Delivery 

We are open f or collection: 
Monday — Friday 
10am -5.30pm 
Saturday 9am -5.00pm 
Delivery by Sccuricor: 
please add 5% 

Smaller items are sent by 
post unless otherwise 
requested. 


10/11 Salisbury Square, Old Hatfield, 
Hertfordshire. 

Telephone: Hatfield (07072) 65551 


• Circle No. 154 


PRACTICAL COMPUTING October 1983 


77 















CP/M's past 

For all its popularity, CP/M could hardly be described as elegant. John and 
Timothy Lee look at what makes it so annoying to use, and find out how many of 
its faults have been eliminated in the new version, CP/M Plus. 




Highest memory 


FDOS 

address— usually 64K 


(BDOS & BIOS) 



CCP 



transient 



program area 



or TPA 


address 100 hex w 



lowest memory 

CP/M jumps and buffers 


address 0 hex — ► 




Figure 1, CP/M 2.2 architecture and memory map. 


decade, during which the CP/M 
operating system has become the de facto 
standard operating system for eight -bit 
micros. It was originally written by Gary 
Kildalfi a consultant to Intel, for use on 
his own Intel development system. 

CP/M — the name is said to stand for 
Control Program for Microcomputers — 
was then developed and marketed by 
Digital Research for the Intel 8080 pro- 
cessor, and subsequently for the Zilog 
Z-80 and Intel 8085-based machines. By 
1975 a growing number of microcomputer 
manufacturers had adapted CP/M to run 
on their hardware, and a large base of 
users began to form. 

One important feature which made 
CP/M catch on was the provision of the 
program ASM. It provided the ability to 
write machine-code programs using 
mnemonics, rather than having io hand- 
code them in hexadecimal. Furthermore, 
such programs would run on any CP/M 
machine, making it possible for people to 
write programs like Microsoft Basic, 

With the large CP/M market, pro- 
grams could be sold at ridiculously low 
prices compared with the price of soft- 
ware for mainframes. In the early days a 
revolutionary word-processing program 
called The Electric Pencil held a position 
of dominance, though in recent years this 
spot has been taken by WordStar. 

The availability of CP/M and its 
dependent software led to the widespread 
use of the Intel 8080 and Zilog Z-80 
central processors. The superior speed of 
the Z-80, which runs at up to 4MHz, 
together with its much larger instruction 
set, made it more popular than the 
original 8080 which can only manage 
2MHz. Z-80s are now available running at 
6MHz, and even 8MHz. The Intel 8085 
which is a code-compatible enhanced 
version of the 8080 runs at 5MHz and 
faster, Zilog’ s forthcoming 2800, a code- 
compatible enhanced version of the Z-80, 
will run at up to 25MHz — see Ray Coles’ 
article in Lhe August Practical 
Computing. 

The battle for dominance of the 16-bit 
microcomputer market is still on. 
CP/M-86 and MS-DOS are strong cont- 
enders For computers based on the Intel 
8088 and 8086, CPUs while several 
variations of Unix and CP/M-68 are in 
contention for the Motorola 68000- based 


machines. Concurrent CP/M, with time 
sharing of the CPU between two or more 
tasks, may prove valuable where the CPU 
is sufficiently fast and powerful. In this 
article, CP/M without qualification will 
refer to the 8080 version of CP/M, release 
2.2, now sometimes called CP/M -80. The 
new CP/M operating system CP/M Plus 
is the long-awaited CP/M -3. 

CP/M does not allow transient pro- 
grams like Microsoft Basic or WordStar 
to access more than 64K of memory. At 
the time CP/M was originally written, 
this limit appeared astronomically large 
and unimportant. Now it is the common 
size. In fact you cannot even get 64K of 
usable memory since CP/M itself 
occupies about 7K, leaving only 57 K if 
you are lucky. If your computer has a 
memory- mapped disc board, or a 
memory -mapped video board, then even 
less memory will available be for your 
program. 

Because CP/M is unable to handle 
more than 64K of memory, there is not 
enough memory for CP/M to buffer 
previously used disc sectors. If such 
buffering were available, sections of data 
on the disc that are frequently used would 
be held in buffer memory and would give 
almost instantaneous program load- 
ing. Programs that make extensive use of 
overlays — WordStar is one — or those 
word-processors and data-base programs 
that manipulate large files would run 
much faster. Some manufacturers have 
simulated a disc drive using RAM to get 


round this deficiency. Such devices are 
variously known as RAM discs, virtual 
discs, silicon discs or semidiscs, examples 
being Warpdrive, Semidisk, M-Drive, 
RAM Disk and Interstellar Drive. 

CP/M Plus can be configured in two 
different ways. The simplest form uses up 
to 64K of memory, like previous releases 
of CP/M, and it is called non-banked. 
However, CP/M Plus also supports mul- 
tiple banks of memory and this version is 
called banked. 

Configured in banked mode, CP/M 
puts the TPA user memory in bank 1 and 
moves most of CP/M to bank 0. Only the 
top 4K of the users bank of 64K is needed 
by CP/M, and this 4K must not be bank- 
switching — that is, the top 4K must 
appear in all banks. This leaves a larger 
TPA of 60K. In the banked version, the 
CCP is kepi permanently in memory in 
bank 0, so it takes practically no time to 
return to CP/M command level. 

To display the names of the files 
present on the logged-in disc CP/M uses 
the Dir intrinsic command. This is fine, 
but the command is slow. Dir works by 
reading through the file-directory space as 
stored on disc, starting at the beginning 
and continuing entry by entry until the 
end. Each time a non-deletcd file is 
found, the name of the file is printed. 

Equally important, each time a 
program opens a file, or looks for a file, 
or a new file extent — that is a new 16K 
section of a disc file — CP/M has to 
search sequentially through all of the 


78 


PRACTICAL COMPUTING October 1983 


Operating systems 










and present 



Gary Kildall, president and founder of 
Digital Research, is the primary architect 
of CPM* 


directory entries to determine whether the 
file exists. This is painfully slow and is 
simply not necessary* Techniques like 
hashing the directory would reduce the 
number of disc accesses needed to find a 
file. 

Directory handling has been improved 
considerably in CP/M Plus as directories 
are now hashed* When CP/M Plus is 
asked to create a file, an algorithm 
calculates into which entry of the 
directory the file should go. If this entry is 
empty „ the file name is put there, 
otherwise the algorithm produces another 
entry to try, and so on until an empty 
entry is found* If an empty entry cannot 
be found, then the directory is full. 

When CP/M Plus accesses a file, it 
calculates in which entry in the directory 
the file name is likely to be, and looks 
there* The file name will usually be there, 
but if another file name is found, CP/M 
Plus tries the next entry where the file 
name might have been put, etc. If CP/M 
Plus finds an empty entry before the file 
name is found then the file does not exist. 
Thus CP/M Pius usually only looks at 
one or two entries in the directory to find 
a file and does not search linearly through 
all the directory entries as CP/M 2.2 did. 


This results in files being searched for, 
opened or created much faster. Since files 
have a directory entry for every 16K of 
data, this results generally in faster disc 
access times. 

There Is little provision for redirection 
of output. If your CP/M has the lObyte 
implemented, then you can use Stat to 
change the console device to any one of 
three physical devices. But on many 
copies of CP/M the lObyte is not implem- 
ented, You may want to run a program 
and redirect the output which would 
normally go to the screen to a disc file, or 
to a printer. CP/M allows the user to type 
Control- P for all messages which are sent 
to the console to be copied to the printer. 
Unfortunately this does not work when 
running some proprietary programs like 
Microsoft Basic. 

CP/M does not allow you to send 
console output to a disc file instead of 
a terminal, It is only possible to copy 
output to the printer, and it is not possible 
to copy console output to a disc file, so it 
is not possible to create a file containing a 
sample run of a program. 

Similarly CP/M provides only poor 
facilities for redirection of input. The 
transient command Submit allows CP/M 
commands to be read from a file rather 
than from the keyboard, and Xsub allows 
command lines to be passed to applic- 
ations programs* However, these 
commands only support the passing of 
command lines. They do not allow single 
characters to be read from a file rather 
than typing them from the keyboard. 
Thus any program that has character 
commands rather than command lines 
which have Return at the end of the lines 
— WordStar for example — cannot be 
driven using the facilities provided. It 
should be possible to read input data from 
a disc file instead of typing it from the 
keyboard, and redirection facilities of this 
type exist on all mainframes. 

True redirection of Input and output is 
now available on CP/M Plus using the 
new transient commands Gel and Put, 
Input can now be taken from, or output 
sent to disc files. 

Input from the keyboard is not 
buffered by CP/M, During a slow disc 
operation the CPU is not listening to the 
keyboard, and anything you type during 
this period will be lost. A good operating 
system should check periodically to see 
whether characters have been typed on the 
keyboard, and store them in a buffer until 
the program that is running asks for input 
data. This form of keyboard buffering 
would prevent characters being lost when 


disc access occurs on a word processor* 

Early versions of CP/M were designed 
exclusively for Sin. IBM single-density 
format discs. The basic units of the IBM 
format were the track and the sector* 
Discs had 77 tracks and each track had 26 
sectors. Each sector contained 128 bytes 
of data* CP/M was, and still is, organised 
around sectors. Files are read or written in 
128-byte sectors. 

Most disc boards now read or write 
more than 128 bytes at a time. For 
example, IBM double-density puts 256 
bytes in each sector, and North Star 
double density puts 512 bytes in each 
sector* Meanwhile CP/M still works by 
reading or writing 128-byte chunks of 
data that CP/M still calls sectors. Thus 
one, two or four CP/M sectors equal one 
disc sector. CP/M would run more effic- 
iently if it could be set to work in the 
appropriate multiples of 128 bytes* 

The way CP/M reads discs is wasteful* 
When a request is made to read a sector 
from disc, CP/M moves the disc head to 
the correct track and watches the data 
passing under it until the required sector is 
seen. The data is then read into memory* 
The next file to be read will probably be 
for the next sector, and it is likely that this 
sector will be on the same track as the 
previous sector* 

CP/M would run faster if it read and 
buffered the whole track as soon as the 
track is first used. Subsequent accesses for 
this track would then read the data from 
buffer memory rather than from the disc, 
and thus would be very quick indeed. 
Track buffering is not implemented in 
CP/M although some manufacturers 
have developed special versions of Bios 
that buffer a track, for example Turbodos 
by Software 2000 Inc. 

In the banked configuration of CP/M 
Plus any spare space in bank 0 can be used 
by CP/M lor disc buffering, as can up to 
another 14 banks of 60K. The total 
amount of disc buffering available is thus 
over 850K if sufficient memory is 
available. Both the banked and the non- 
ban ked versions allow a sector count to be 
set, CP/M always then communicates 
with the disc system in the multiples of 
sector- count CP/M sectors* Thus CP/M 
can be made to work in units of the disc 
system, or even in tracks. 

One of CP/M’s annoying and un- 
necessary features is the need to press 
control-C to log in a new disc each time 
you change discs. Cromemco found how 
to avoid doing this many years ago with 
its CDOS operating system* If you change 
(continued on next page) 


PRACTICAL COMPUTING October 1983 


79 


Operating systems 


unusable 


banked 

BDOS and BIOS 


CCP 


other space in 
bank is for 
disk buffering 


64 K 


60 K 


100 hex 

0 hex 


CP/M 

(buffers) 


part of BIOS and BDOS 


transient 
program area 
or TPA 


CP/M jumps and buffers 


Bank 0 


Bank 1 


Figure 2. Memory map for banked CP/M Plus. 


(continued from previous page) 
discs and do not press control-C then the 
first time you try writing to the changed 
disc, CP/M will stop with a BDOS error. 

Copying a whole disc is tedious and 
slow, using Pip to copy the files, and 
Sysgen to copy the operating system for 
the reserved tracks on the disc. It would 
be more convenient, and much quicker, to 
have a utility program to copy an entire 
disc track by track. 

With CP/M Plus it is no longer 
necessary to type Control-C every time a 
disc is changed. If u tries to write on a disc 
CP/M Plus detects that the disc has 
changed and no longer gives BDOS error 
R/G, Instead it logs the new disc in and 
does the file write* This improvement 
should remove one major source of frust- 
ration of using CP/M. 

CP/M Plus will also search all discs for 
a program before giving up with an error 
message. The order in which the discs are 
searched can be set by the user. Failing to 
shut the disc door is not fatal. 

Even better, an application program 
can put CP/M Plus in a mode where 
CP/M Plus never reports an error, but 
sends a Return code back to the program, 
indicating that the desired function has 
not been achieved. Using this facility 
application programs can be rewritten to 
put an intelligent error message on the 
screen, stating the source of the problem 
and indicating what remedial action 
should be taken. 

CF/M’s console command processor, 
CCP, only looks on the currently logged- 
in disc for files. It would be more friendly 
if all discs were checked, starting with the 
logged-in disc. 1 f the CCP cannot find the 
file on any disc then a message lq this 
effect should be printed rather than just 
the file-name and a question mark. 

It is annoying if you type a command 
line with a spelling mistake and press 
Return. The CCP does not let you edit the 
erroneous line to take out the spelling 
mistake — the whold line has to be retyped 
instead. 

There is a considerable delay when 
returning to the system from a transient 
program. For example, when you type 
System to get out of Microsoft Basic to 
return to CP/M, there is a considerable 
delay before the CP/M system prompt 
A > appears. This is because the transient 
program may overwrite the CCP, and on 
returning to CP/M the CCP must be read 
from disc, and reloaded into the approp- 
riate pan of memory — see figure l . 

The transient program ASM, which 
contributed much to the early success of 
CP/M, is now very dated. It still works 
perfectly well, but only accepts the 80 
instructions in the 8080 instruction set, 
thus preventing use of the extra 80 
commands in the Z-80 instruction set. 

In CP/M Plus the old ASM program 
has been replaced by a macro assembler, 
which can also assemble Z-80 code. The 
lObyte redirection facilities have been 


taken out of Stat and made into a new 
easy-to-use program. A Help system is 
also supplied for CP/M. The database 
used by the Help program can be cust- 
omised using programs provided. 

You can also add help on completely 
new topics, such as applications programs 
that you use, or instructions for backing 
up discs, etc. Pip now has the ability to 
archive files. Used this way, Pip copies all 
files that have not previously been 
archived, and also marks the file as 
archived. It makes the task of backing up of 
big hard discs onto floppies slightly more 
tolerable. 

New machines will probably use CP/M 
Plus rather than CP/M 2.2, as the banked 
version provides far faster file handling. 
Installing CP/M Plus will be difficult: 
Digital Research does not plan to sell 
CP/MPIusto end-users but dealers will be 
able to configure and sell versions for their 
machines. 

Those micros that can have lots of 
memory — for example, all S-100 
machines — will benefit greatly from the 
change from CP/M 2.2 to CP/M Plus, On 
many micros the discs are the biggest 
bottleneck, and CP/M Plus dramatically 
improves disc throughput. 

For those who cannot wait until a version 
of CP/M Plus is available for their 
machine, a dramatic improvement in 
computer performance can be achieved by 
buffering some of the disc in memory. It 
can be done from CP/M 2.2 with 
software that is in the public domain and 
published in Lifelines from Lifeboat 
Associates. 

Alternatively you can purchase 
Warpdrive from Compupro, Semidisk 
from Semidisk Systems Inc., M- Drive/ H 
from Compupro for S-100 systems, RAM 


disc for the Sage, or Pion’s Interstellar 
Drive for a wide variety of machines, 
including S-100 systems, IBM, Tandy and 
Apple, They all provide the extra memory 
and the software to make it work, usually 
on a configuration disc. 

Effectively these add-ons work by 
kidding the system into believing that a 
256K or 512K memory board is really a 
disc drive. You can copy files from a 
floppy on to it and use them, if you alter 
the disc file, then you must copy the new 
file back on to a real floppy disc before 
switching off, 

A cheaper and more subtle approach is 
to use extra memory as a cache, where 
only the frequently used disc files or parts 
of files are buffered. This works with 
quite a small amount of memory. From 
4K upwards. Obviously more memory 
makes it work better. When the buffer is 
full, the least recently used part is the first 
to be discarded. There are two suppliers 
of this type of system, both British* Ghost 
Is from Micrology, 4 Deanery Road, 
Godaiming, Surrey GU7 2PQ, and Micro- 
cache, is supplied by Microcosm Research, 
26 Danbury Street, London N1 8JU* 

Cifer U.K. is a beta test site for CP/M 
Plus and is already selling machines with 
the new operating system. Sirton is also 
selling CP/M Plus in the U.K. Other 
dealers will probably follow shortly* 

It seems likely that CP/M Plus will add 
extra life to the eight-bit micros based on 
the Z-80, At present the I6-bii machines 
offer the promise of much more power, 
but good 16-bit software Is still lacking. 
Mark Twain said, ‘"Rumours of my death 
are greatly exaggerated” — and the same 
is true for the Z-80. In many applications 
CP/M Plus will increase the throughput, 
giving more delivered power* Q 


80 


PRACTICAL COMPUTING October 1983 


If your microcomputers job involves managing information, you'll need a Compsoft Data Management 
System. It’s your guarantee that computerisation will be a success. 

Compsoft are world leaders when it comes to easy to use database programs. There is nothing quite so 
genuinely user friendly, and nothing quite as powerful. And Compsoft were the winners of the 1983 RITA 
(Recognition of Information Technology Achievement) Awards ‘Software Product of the Year’. 

We can give your ' H Computer the power to breeze through the management of any record keeping 
situation, — effortlessly, efficiently, and more accurately than you ever dreamed possible. From sales 
ledger to stock control, purchase ledger to personnel, clubs to customers, and in a thousand other ways, 
we can lend a helping hand. 

You don’t have to be a computer expert to use Compsoft’s DMS or Delta. Both programs offer fast, 
accurate and elegant database power for both first time computer users and professional systems designers. 

You owe it to yourself to know more. Either return the coupon to us, or simply telephone the office and 
we’ll send you a complete guide to our versatile database programs - today. 





' 0 + 




* Delta is available for almost any microcomputer 
with the MSDOS, PCDOS, CP/M or MP/M 
""‘‘ftpesaLjjig systems, including IBM, DEC Rainbow, 
SIRIU^XEtm^MCL, EPSON - and many others 


CompSoft 

Data Management 
Systems 


the delta 


DMS is also available for Commodore computers. 1 




Compsoft Limited 


Mease send me further details 





l lallams Court 

Sham Icy Green 
Nr Guildford, Surrey 
England GU4 80/ 
Telephone: Guildford (0483) 898545 
Telex: 859210 CMPSET 


Company 

Contact 

Address 


PC 


Tel No. 


• Circle No. 155 


PRACTICAL COMPUTING October 1983 


81 


Backgammon 

between the casing of the cassette and 
the display on the computer screen 
Backgammon seems to change its name to 
Micro deal Pen gammon, probably for 
some inscrutable copyright reason. Ail the 
same it is the traditional game of 
Backgammon. 

The program allows the computer to 
play against you or against itself; 
alternatively you can use it instead of a 
board to play with another human, 
although I cannot see many people 
wanting to given the Dragon’s typical — 
literally — scintillating display. 

The screen displays red and yellow 
pieces on a green background. Moves are 
made by typing in the source and 
destination square numbers, although you 
can use MicrodeaFs light pen if you have 
one. You need to know the rules of 
Backgammon as neither the screen display 
nor the packaging help you, and you have 
no option but to play the doubling game. 
If the Dragon offers to double the stake 
and you refuse you have lost. 

The game has nine levels of play. You 
can cheat by changing the machine’s level 
of play during the game or you can get 
the machine to make your moves for you. 
The machine seemed to play quite well at 
its top level, but to be honest I did not 
find playing Backgammon against a 
machine sufficiently exciting to provide it 
with much of a challenge. 

Specification 

Supplier; Microdeal 
Price; £8 

Use of graphics: 6/20 
Playability: 12/20 
Overall rating: 9/20 

Cruising on 
Broadway 

cruising on Broadway is one of the few 
games to make the transition across from 
the Spectrum to the Dragon, and is quite 
a playable game although it is very 
simple. It has no discernable connection 
with anything as realistic as Broadway, or 
for that matter with cruising. 

You are a green blob and you are 
chased by a yellow blob through a simple 
maze. Success promotes you to higher 
and progressively more complex mazes 
until you are eventually eaten. However, 
your name will live on in the high 
scoring hall of fame if you can survive 
sufficiently long. 

Cruising has simple graphics and 
sound effects to match, but ii is quite 
compelling and exciting. In fact, the 
Sunshine logo which comes up as you 
load the game is one of the best examples 
1 have seen of what can be done with 
Dragon graphics, although the screens 
you play on are far less elaborate. 


Dragon 

games 

Ian Stobie was not very impressed with the selection of 
games he tried for this machine. 



Cruising on Broadway is a game of survival, you can never actually win. 



82 


PRACTICAL COMPUTING October 1983 






Games 


Given the generally poor standard of 
the 30 or so Dragon games I looked at 
Cruising must rank as one of the better 
games available for the machine. 

Specification 

Supplier: Sunshine 
Price: £6,95 
Use of graphics: 8/20 
Playability: 12/20 
Overall rating: 10/20 

Gridrunner 

so much goes on in this game it is 
difficult to describe, it is like a cross 
between Space Invaders and Centipedes. 
Your little orange ship is being chased by 
linked chains of droids across the high 
energy lattice, the grid. You draw power 
from the first seven rows of the grid, 
which you zoom around while firing at 
the droids. Meanwhile the deadly X/Y 
zappers try and get you from the side of 
the grid. 

Gridrunner is a top selling game on the 
Vic-20 and Atari. The Microdeal Dragon 
version is credited to the same author, 
Jeff Minter, but it is not as good. It 
seems slower* the graphics are not as 
good, and generally it is less exciting. 

Much of the problem can be attributed 
to a less effective use of sound; the game 
needs lots of noises to generate a sense of 
excitement. In this version you do not get 
a noise when you fire. Still* while not 
initially very compelling Gridrunner is a 
good game if you persevere. 

Specification 
Supplier: Salamander 
Price: £7.95 
Use of graphics: 6/20 
Playability: 13/20 
Overall rating: 10/20 


Dragon Trek 

there are several versions of the classic 
computer game, Star Trek* available for 
the Dragon and Dragon Trek from 
Salamander was the best of the three I 
looked at. It goes beyond the typical text 
mode display and has reasonable 
graphics. The game takes place in real 
time so you cannot take too long over 
your decisions. 

You start by setting the difficulty level* 
0-9* and length of game. Your task is to 
take command of the USS Enterprise and 
patrol the galaxy* eliminating deadly 
Klingoms to save the Federation. Your 
ship* armed with three types of phasor 
and with photon torpedos, is protected by 
shields. The problem is to correctly use 
your limited amount of energy. This is 
used up at an alarming rate whenever 



Ga lactic Ambush ic is a n arcade game. 



Gridrunner is not as good as on the Dragon. 



Dragon Trek is just one version of Star Trek available for the Dragon. 


your shields are hit by a Klingon* when 
you fire back* or when you warp or use 
your impulse jets to move. 

This is quite an enjoyable game, but it 
is still not a patch on the best* truly real- 
time versions oT Star Trek for other 
machines* for instance* Star Raiders on 
the Atari. 

Specification 

Supplier: Salamander 
Price: £9.95 
Use of graphics: 9/20 
Playability: 13/20 
Overall rating: ] 1/20 


Galactic Ambush 

GALACTIC AMBUSH is a Galaxians-type 
arcade game. Aliens steadily advance 
from the top of the screen, occasionally 
leaving formation to come at you with 
missiles blazing. You shoot back. 

Visually the game is quite good by 
Dragon standards — the best thing is the 
three-dimensional moving star field 
against which the action takes place. But 
even at the fast speed the game is rather 
too easy to play. 1 doubt if it will provide 
much of a challenge to the average mad 
gamester for very long. 

Specification 

Supplier: Microdeal 
Price: £8 

Use of graphics: 12/20 
Playability: 6/20 
Overall rating: 9/20 


Wormtube 

WORMTUBE IS a kind of crude Defender* 
but It is quite enjoyable. You fly your 
ship through a steadily narrowing tube* 
scoring more points the futher you get 
along it. Gold nuggets appear in your 
path, which you have to avoid or shoot 
apart. You get extra points for gobbling 
up the fragments of shot-up nuggets. 

Up to four people can play Wormtube 
taking turns with one joystick. The 
graphics are quite simple but adequate* 
and the game is made more exciting by 
the noises which rise in tone as your score 
increases. This game reminds you that it 
Is not alvyays the most complicated effects 
that work best. One of the best things 
about the original arcade Space Invaders, 
for instance, was the steady insistent 
noise the ever-more determined invaders 
made as they came ai you. 

Specification 

Supplier: Hornet 
Price: £8 

Use of graphics 6/20 

Playability: 13/20 m 

Overall rating: 10/20 ™ 


PRACTICAL COMPUTING October 1983 


83 





Buy a 1 0 pack of Control Data 
flexible disks and get one free in 
every box. 

top quality flexible disks from 
Control Data, the company which 
sets the industry standard for all 
magnetic media. 

Available in SYT'and 8"sizes and 
m ost popular form ats. 

These Bonus Packs are only 
available from the Control Data 
Distributors listed next to this 
advertisement 
Phone today 
for further details 

of this unbeatable GONTI\DL 

offer DATA 


84 


• Circle No. 156 

PRACTICAL COMPUTING October 1983 


Call your A 
nearest 
Bonus Pack 
stockist today: 

BIRMINGHAM 

Media Resources - 021-643 9940 

CAMBRIDGE 

Jeffrey Sirvjoc & Associates Ltd 
(Cam bridge) -0223-321 000/ 321333 

CLEVELAND 

E.W. Harrison & Partners (Hartlepool) - 0429-79314/5 

HAMPSHIRE 

Plum Business Services Ltd (Portsmouth) - 0705-736626 

HERTFORDSHIRE 

Churchill Computer Supplies Ltd (Bushcy) - 01-950 9510 
Data print Paper Supplies Ltd (Letch worth) - 04626-78394 

HUMBERSIDE 

Contrac (UK) Marketing (Hull) - 0432-571741 

IRELAND 

Cantec - Dublin 694455 
KENT 

Salmons Computer & Office Supplies 
{ Northfleet) - 0474-57261/234 7 5 

LANCASHIRE 

Pegasus Computer & Business Supplies 
(Nelson) - 0282-68191 
LEICESTERSHIRE 
Elmhurst Computer Services Ltd 
(Oakham) - 0572-5742 3/5S3 29 
LONDON POSTAL DISTRICTS 
D.W. (Direct Wholesale) Ltd (NW9) - Ql-205 3476 
Scopus UK Ltd (EC2) -01-739 3344 
VBK Computer Supplies Ltd (E4)-G1-524 6303/4/5 
KMWespac Ltd (El) - 01-729 1170 
MANCHESTER 

GC.S. Computer Services - 061-339 0400 

MIDDLESEX (Norlh) 

Kendal Computer Group (Enfield) -01-366 1411 

MIDDLESEX (West! 

DI-MOS Ltd (Hillingdon) - 01-561 6460 
Libra Business Supplies Ltd (North wood) - 09274-28598 
PAS Computer Products Ltd (Staines) -Q7B4-62 781 
Warwick Fraser {Felt ham) - 01-844 2T44 
NORFOLK 

Board mead (Last Anglia) Ltd (Norwich) - 060 3-483659 

SCOTLAND 

Aberdeen Computer Services Ltd 
(Aberdeen) -0224-875867 
Datamart - (Edinburgh) - 031-441 6961 
SOMERSET 

Guildhall Computer Stationery Ltd 
(G las tun bury) - 04 58-34122 

STAFFORD 

Associated Computer Supplies Ltd (Stoke) -0782-287121 

SURREY 

Saracen Data Products Ltd (Dorking) - 0306-887550 
Tarhot Computer Services Ltd (Sutton) - 01-642 0021 
WBM Business Supplies Ltd (Woking) -04862-66441 
SUSSEX 

Hayfurm Ltd ( Horsham) - 0403-71 08 18 

SBS Data Services Ltd (Hove) -0273-726 331 

Scan Computer Supplies Lid [Burgess Hill) - 04446-4521 1 

WILTSHIRE 

Strailbrs Data Products Ltd (Swindon) - 0793-37837 

YORKSHIRE 

Diskatecb Ltd (Sheffield) - 0246-410377 
Nevetsco Ltd (Sheffield) - 0742-452051 
Spectrum Computer Supplies (Bradford) - 0274-308188 

TWIN LOCK 

Bonus packs are also available From your local 
TWI N LOCK dealer. 

Details of your nearest dealer are available from:- 
Twinlock (London and South) -01-658 5931 
Twinlock (Midlands and North) -021-565 2906 
Twinlodt (Scotland) -041-445 4421 



CONTRpL 

DATA 




hunt 


whats YOUR FAVOURITE computer game, and 
why? What kind of game is it? What’s your best 
score? How does the game rate against Scrabble on 
the Apple, The Hobbit on the Spectrum or Star 
Raiders on the Atari? Consult the ratings published 
in our regular games reviews for comparison. 

Then fill in the software survey form below and 
let us know. The results will be collated for a 
special guide to computer games in our December 
issue, including a Top 30 as selected by readers of 
Practical Computing , 

You can fill in a survey form for more than one 
game. Simply photostat the one below. 


! ' I 

I Game: — .... 

Publisher: ........... 

Machine: . — ........ 

RAM required: - 

Accessories required: 

Price: ..for cassette/disc/ROM 

3k # * 

j Type of game:. . - 

| ...Frogger, Scramble, Pacman type, etc. 

Number of players: to 

I Object of game:..... - 


Use of colour/sound: 


Comments: 


Your highest score: — 

Rating out of 20:..... 

# * 

Name: 

Address:.... 


Post completed forms to: BIG GAME HUNT r Practical 
Computing , Quadrant House 5 The Quadrant, Sutton, Surrey 
SM2 5AS to arrive by Friday September 30> 1983, 


| Optional 


85 


PRACTICAL COMPUTING October 1983 



Oh, so easy WP 


Jack Schofield found Atariwriter convenient, easy to use, and relatively cheap. 


POWERFUL WORD PROCESSORS are 110 
stranger to the Atari computers: Letter 
Perfect , Text Wizard and the Atari word 
processor have been out for three or four 
years. But the new ROM-based Atari writer 
represents a breakthrough in terms of 
convenience and ease of use, especially for 
the 16K 400 owner who will be able to use it 
even with a disc system. 

It is also, while virtually as powerful, 
cheaper than some of its rivals. It costs 
about a third less than the Atari WP and is 
half the price of the Letter Perfect ROM, 
though it is somewhat more expensive than 
the product it most resembles — Computer 
Concepts’ Wordwise ROM for the BBC 
micro. 

Atariwriter was developed by Atari 
partly from the Atari WP, in conjunction 
with Datasoft who produce Text Wizard. It 
has something in common with both 
parents, but is most like Text Wizard in its 
insert mode. Like Wordwise, Atariwriter 
operates permanently in insert mode so 


there is no overwriting. As you type text 
into the middle of a paragraph existing text 
is pushed down the screen a word at a time. 
This creates some odd effects at line 
endings but is eminently practical. 

As with all Atari’s main-line programs 
the documentation and packaging are 
outstanding. Atariwriter comes with a slim 
manual which includes tutorial and 
reference sections, plus a handy Quick- 
reference card. Interestingly the doc- 
umentation is better than the massive 
volume and tape provided with the Atari 
word processor. 

To run you just plug it in. The program 
has two main screens with legible white text 
on a darkish blue background, darker than 
the usual Atari screen. First is the menu 
screen with eight options: Create, Delete, 
Edit file, Format disc, index of disc files, 
Load, Print and Save file. Options are 
selected by typing the first letter of each 
word which is shown in inverse type. 

The second screen provides a 21 -tine by 


36-charaeier space for text entry, which is 
less than the Atari’s standard 4Q-by-24 
format. The top line initially contains the 
default parameters for printing. These can 
be changed or added to later. 

Anyone can use the program without 
knowing anything about word processing, 
just by typing C and then entering text. The 
more sophisticated user will learn to use the 
other functions like block moves and 
Search and Replace. These are invoked 
using combinations with Control, Ctrl, and 
the Atari’s three programmable function 
keys marked Option, Select and Start. 

The initial menu screen is self 
explanatory and provides some access to 
Atari DOS functions. Index rapidly 
alphabetises the list of files, and its scrolling 
is stopped and started with the space bar. 
Any function which destroys text or files 
requires an “Are you sure — ■ Y/N”, 
confirmation. You can always get back to 
the menu screen by pressing Esc for Escape. 

The text-entry screen provides a 



A V* CVttJ? P-MKW&OX 
) OR All ATARI 


Atariwriters main menu. 




Typical Atariwriter screen. 


The manual includes tutorial and reference sections. 


86 


PRACTICAL COMPUTING October T 983 



Word processing 


reasonable range of cursor movements for 
editing. The basics are handled by the 
standard Atari full-screen editor with four 
direction keys, which with Ctrl move you 
one step at a time in any direction. There is 
full scrolling up and down, though up- 
scrolling is a bit jerky. You can go up or 
down one screenful at a time by Option t 
and Option 

Four other movements are exactly the 
same as in Text Wizard. Ctrl A moves the 
cursor to the start of the line, and Ctrl Z 
moves it to the end. Select T takes it to the 
top of the text, Select B to the bottom* 
There are no word, sentence or paragraph 
movements. 

Deletions are equally simple, by 
character and by line, using the Delete Back 
Space key, DBS for short* Select DBS 
deletes to the end of the file, A 30-line 
buffer holds the last thing you deleted, so it 
can be recovered by pressing Start Insert. 

The buffer also provides for block moves 
and block duplication. Each block has to be 
defined by marking its start and end with a 
Ctrl X. Again, block deletes require a Y 
answer to an “Are you sure?” Search and 
Replace can be individual on the same Y/N 
basis, or global. The maximum length of a 
search string is 25 characters — more than 
generous* 

It is always possible to find out how 
much space remains for text by pressing 
option F. At this point using a 48K Atari 
800, for example, 12,941 bytes — or 
characters — remain free, so this report will 
consist of a single continuous file. 
Atariwriter warns you when there are only 
1 ,500 bytes left* The Atari WP has no limit 
but you must produce text as a series of 
saved pages. The memory limits of Letter 
Perfect and Text Wizard are 36,714 and 
1 30,505 bytes respectively, compared with 
Atariwriter^ initial 26,332 without DOS. 

Texts can be merged so it is possible to, 
say, load a text from disc into the middle of 
an existing file. Also print files can be 
Chained, a way of handling long articles. 


After the text has been entered the next 
step is formatting for printing. Here 
Atariwriter is at its weakest because it is 
limited by the Atari's 40-column screen. 
One option would be to scroll the screen 
horizontally to provide a sort of 80-column 
screen, ftfhich is what the Atari word 
processor does, just like WordStar on the 
Osborne and Magic Wand on the Apple 1 1 . 
There are 80-column boards for the Atari, 
which Atariwriter does not mention. 
Software can also provide 80 columns, 
though of course the text would not be 
legible on a TV set. 

What Atariwriter does instead is provide 
a print preview facility, Option P, where 
the text is set out as it will be printed and the 
screen forms a window which can be 
scrolled over it. Thus it is possible to check 
line and page endings and margins, though 
it is not very convenient. Many would 
prefer the Atari word processor preview 
option also adopted by Word wise on the 
BBC, where the text is displayed as it will be 
printed even though it is illegible* 

It does not show how expanded or 
condensed text will be printed, nor 
proportional spacing if the printer is 
capable of it* Also although Atariwriter 
will print double columns, these are pre- 
viewed one under the other not side by side. 

Being limited to a 36-character screen 
width for text entry only becomes a real 
problem when trying to set out tables using 
the Tab key. Lf the table is for condensed 
printing across the maximum 132-character 
width you really have to construct the table 
on paper, then type it in afterwards. 

The print parameters can be set in half- 
lines for the bottom margin, top margin, 
paragraph spacing, line spacing and page 
length* Widths can be set in characters for 
left and right margins for two columns, and 
for paragraph indent* Justification can be 
on or off* All of these can be varied within a 
file. Lines can be ranged left, right, or 
centred. Ctrl 0 allows decimal codes to be 
sent to non- Atari printers, such as the 



The package is on disc and cassette* 


Epson MX-8G used to print this text. 
Headers and footers can be handled simply 
with @ providing page numbers. Ctrl E can 
be used to force the start of a new page. 

The final printing out is simply a matter 
of selecting a printer from the list of four 
Atari models — select number 3 for a non- 
Atari printer, and following the screen 
instructions* You can start and stop at any 
page and print multiple copies. 

There is no Mailmerge capability, as 
there is with Letter Perfect in conjunction 
with Data Perfect, but there is a forms 
capability. If you put an Option Insert 
character in the text the printer stops ai it 
and waits for an entry — up to 35 
characters — from the keyboard. The catch 
is that the text is not displayed on the screen 
during printing, and the rest of the line to 
be filled is probably in the printer buffer* 
The system is usable if you are careful* 

There are a few other facilities missing 
from Atariwriter — and all the other Alari 
word processors mentioned. None let you 
interrupt and resume printing — 
Atariwriter allows a pause at the end of a 
page. None will print one file while editing 
another, or display a second file. None 
does automatic file back-up. None allows 
the use of macros to insert key phrases 
with a single key-stroke, or the use of wild 
cards in a Search and Replace operation. 
None provides for soft hyphenation to 
help with the even spacing of lines. While 
Atariwriter and its rivals have many 
qualities, they are not going to replace 
WordStar and its ilk for the serious writer, 
though of course it does not aim to. 

Conclusions 

• Atariwriter is a powerful word 
processor, well documented and extremely 
easy to use. It is easier to learn than Atari’s 
Star Raider game, which is supplied on the 
same kind of ROM cartridge. 

• It is suitable for most everyday writing 
tasks, and coped admirably with the writing 
of this article* It is not comparable in power 
to the best CP/M word processors, but 
provides word processing at a fraction of 
the price. 

• It runs on any Atari micro and can 
happily be used with discs even on a 16K 
400 system. 

• At around £65 it is good value and can be 

recommended. Q 



Atariwriter 

Atari WP 

Text Wizard 

Letter Perfect 

Menu driven 

Yes, one 

Yes, many 

No 

Yes 

Text insert mode 

Yes 

No 

Yes 

No 

Global search/replace 

Yes 

Yes 

No 

No 

Horizontal scrolling 

Only in 
preview 

Yes 

No 

No 

Print preview 

Via window 

Yes 

No 

No 

Double-column printing 

Yes 

Yes 

Yes 

No 

Prints half-lines 

Yes 

No 

Yes 

No 

Can edit programs 

Yes 

No 

Yes 

No 

Mail merge 

Pause for text entry from 

No 

No 

Extra 

Extra 

keyboard 

Yes 

No 

No 

No 

Disc interface 

Atari 

Atari 

Atari 

LJK 

Medium 

ROM 

Disc 

Disc 

Disc or ROM 

Producer 

Atari/ 

Datasoft 

Atari 

Datasoft 

LJK 

Price 

£65 

£99.99 

£68.95 

£109.95, disc 
£149.95, ROM 


This table is not a comprehensive comparison of products, but shows how Atariwriter 
combines most of the best features of its rivals. 


PRACTICAL COMPUTING October 1983 


87 





VIC 20 


Excellent design, inexpensive 
and just what a VIC 20 needs. 
Increases RAM and ROM and 
allows simultaneous use of 
such facilities as VICMON and 
SUPER EXPANDER. 


MGTTAL ELECTRONICS 

A must for today’s technology. 
Introductory course written and 
designed by experts for both 
beginners and students. Practical 
projects and theory for a thorough 
background in this essential 
subject. 

Series begins this month and is 
ideal for ‘O’ and A’ level students 
and all Hobbyists. Recommended 
by the BBC for further reading. 


PHOTOGRAPHIC RESEARCH 

Electronics control the art of 
photography— find out more from 
our investigation. 

Keep ahead with 

PRACTI CAL 


ELECTRONICS 

ON SALE EARLY SEPTEMBER 


ATTENTION ALL popple USERS! 

IflEGAFlLE 


At last the Hard Disk 
Sub System at Floppy prices. 

looking for MEGAFILE. 

Original hard 

XSS. . n»w MEGAFILE 

cuts the cost. 

Acs ' acii Fka floDDV lookalike which allows the 
MEGAFILE ls_ p p H CAL C P/M systems— even 

user to run DOS. P changing a single 

a" ^ree v '"e^with a back up device 

command. Why both ® acity drives at "Low 

when you can buy 9 the extra low cost 

” St adwSta P cEu?voar important data. Drives 


MEGAFILE comes in 5MB, 10MB, 20MB, | 

Wl cjlkiuir and 10+1 0MB versions. 

system prices start at 
£895 dealer enquiries welcome. 


For more information contact: 

fi Rf II IMA RHAn i nwnnw «utn /ici tei couin 


• Circle No. 187 

PRACTICAL COMPUTING October 1983 


• Circle No. 158 



Vertical Market Software 
f rom Padmede 



The Restaurant Package 
Specially developed for 
Restaurants who want to 
easily produce a Customer's 
Bill; maintain financial control 
of cash, credit card and [ On 
Account 1 sales, as well as 
maintaining Stock Records 
and Management Information. 


The Travel Agents 1 
Package 

Specially developed for Travel 
Agents, PATAP provides 
control over Airline Ticket 
Reservations and 
automatically produces Airline 
Sales Reports. Analyses sales 
by cash, credit card and 'On 
Account', while automatically 
updating the Purchase Ledger 
Account for the Airline 
concerned. 


The Garage/Workshop 
Package * 

Specially developed for the 
Garag e/Work shop 
environment, PAGAP records 
Time and Materials used for 
the repair and maintenance of 
vehicles. Provides 
management with information 
on Work in Progress and 
chargeable work by individual 
employees yet to be invoiced. 


The Retailers Stock 
Control Package 
Specially developed for the 
Retailer who wants to know at 
a glance the Current Value of 
Stock over All Products or by 
ranges of Individual Product 
Groups. Provides 
management with information 
on Gross Profit, Turnover, 

Slow Moving Items and 
Outstanding Orders. 


Padmede* s Vertical Market 
Software is available on 
microcomputers supporting 
*CP/M 2.2, CP/M 3.0, 

* MS-DOS and PC-DOS. 
Comprehensive financial 
control is maintained via the 
Padmede Business Control 
System — a suite of financial 
management programs. 


‘CP/H 1 1 Lhfl re-gnlii rad Trade mac k dI Dsnil-n L Htienreh COfp, 
'MS' DOS Li U» rain in rod Tidd-ujji fi rh 4l Microvolt Corp. 





MlRROj 


. . . proven, reliable and easy to use 

Padmede 

COMPUTER SERVICES 


351 Fleet Road, Fleet, Hampshire. 
Telephone: Fleet (02514) 21892. 
Telex: 858893 Fletel G. 







I I would like to discover Ormbe ta, please 
| send me your latest brochure □ 

I am interested in becoming an Ormbeta 
| dealer □ Tick as required. • circle No. 254 

| Name 

* Org 

I Address 


ORMBETA SOFTWARE 


SALES LEDGER 
PURCHASE LEDGER 
STOCK CONTROL 
PRODUCT INVOICING 


HOHIHAL LEDGER 
PAYROLL 

DATA BASE MAIN HEHU 
DATA BASE UTILITIES 


Lancashire L39 3BW 


Ormbeta business software has been 
developed to help your business 
overcome the challenges of the 
I980's and beyond. 

Ormbeta is the most flexible business 
software so far developed in the U.K. 

Ormbeta systems are in UCSD 
PASCAL, the world's finest and most 
efficient operating system. 

Ormbeta can be supplied to run on 
almost any business machine on the 
market. Apple, IBM, Xerox, Sirius, 
Victor, and Sage, and more to follow. 


Ormbeta is already being 
developed for tomorrow's 
machines, such as the Apple LISA. ^ 

Ormbeta includes all the 'off-the-shelf 
packages. Sales and Purchase Ledger, 
Payroll etc, but can also be customised 
to particular requirements. 

If you would like to find out how 
Ormbeta can help you meet the 
business challenges of tomorrow, or if 
you are a dealer and want to help 
others, fill in the coupon today - or 
telephone us now on Ormskirk (0695) 


..Tel. 


p.c. 





Never before has so much been available 
from so little, to so manv. 



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With so many micros on the market, choosing just the right one for your 
business can be extremely difficult. 

But for those with a wise head for value, a keen eye for quality and a good 
ear for a sound investment, the choice couldn’t be easier 

The Sanyo MBC range. A high quality system backed by a full range of 
software and peripheral equipment, that offers the very best possible value for 
money anywhere. 

A well proven range, that’s now been extended to include 3 new micros. 

The MBC4050, a powerful 16-bit micro and two new 8 bit micros, the MBCU50 
and the MBC1250.The latter having the advantage of a full graphic function and high 
resolution 640x400 dot display screen. 

As with all Sanyo equipment, great emphasis has been placed on their 
ergonomic design, thus ensuring the maximum ease and convenience for the 
operator 

If you’re investing in micros, make a wise decision and take a 
look at Sanyo to see whether you’ve got what it takes. 


See Sanyo, Then Decide 

FOR FURTHER INFORMATION CONTACT OUR DISTRIBUTORS, LOGITEK. AT LOGITEK 
HOUSE. BRADLEY LANE. STANDlSH, GREATER MANCHESTER. TEL: 02S7 426644, 
OR CLIP THE COUPON ON THE LEFT AND RETURN IT TO SANYO. 

w ® SANYO 


Do iOU Have what ItTakesTo 
Own A Santo Business Computer? 




— VDPs and graphics?^ 

The state of the 
graphics art 


The computer has had a revolutionary effect on games, business and the film industry 

to mention but a few — but it is still early days. 

rr is ONLY a few years ago, 1976 to be 


precise, that computer graphics meant — 
for most people — Snoopy primed out in a 
pattern of Xs, To watch the old Teletype 
print out a naked lady was really awesome. 

The following year the Pet micro 
brought block graphics to thousands. 
Pictures could be drawn on a screen , not in 
letters but in little squares, lines and other 
useful shapes. Then the revolutionary 
Apple II, in spite of a curious lack of lower 
ease letters, brought user-definable shapes 
and bit-addressable graphics to anyone 
with a lot of ef fort and £2,000 to spare — in 
colour, too. 

Today for under £100 it is possible to buy 
a colour micro that is capable of drawing, 
within limits, almost anything the 
programmer sets his mind lo. Screens, 
whether TV sets or monitors, are the 
universal method of displaying output. The 
teleprinter is worth its weight in scrap metal 
as more and more dot-matrix printers gain 
the ability to print complicated graphics 
which may be dumped straight from the 
screen. 

These developments have had a powerful 
effect on the computer games business. The 
old Pet version of Star Trek, played in 
black and white with two axes and a 
handful of alphabet, pales into 
insignificance when compared to today's 
high-speed all-colour all-action arcade 
games. 

The effect on business computing has 
been quieter but no less revolutionary. It is 
still possible to use a computer to spew out 
columns and columns of incomprehensible 
figures. However, many project managers 
have round that a graphic flow chart has 
more impact. Salesmen and accountants 
have found that an appropriate graph, bar 
chart or exploded pie diagram can make the 
point quicker and more forcefully. Sales 
are going up, or down; the company's share 
of the market looks like this. 

Graphic representations of figures are no 
longer confined to slide shows and audio- 
visual displays. They are commonplace in 
company reports and the financial pages of 
the best newspapers. This is partly because 
with inflation and the chaos of the 
international currency markets, few people 
have any grasp of what figures mean any 
more. The important thing is the trend. 
Graphics provide wonderful opportunities 


for massaging figures into attractive shapes 
— there are lies, damn lies and graphics. 

Cynicism aside, business graphics can 
have a real value, and numerous software 
packages exist to provide any user with the 
facilities to produce them simply. VisiCalc, 
for example, links to Visi Plot and 
VisiTrend. The current fashion is for 
spreadsheet and calculation programs to 
include graphics as part of the package. 
Lotus 1-2-3, Context MBA and TK! Solver 
are examples. Graphics are an essential part 
of integrated operating systems such as 
Apple's Lisa. Companies like Hewlett 
Packard, Rikadenki and many more have 
developed the plotters which will draw 
suitable graphics with multicoloured 
precision. 

Microcomputer graphics has cornea long 
way in the last five years. Nonetheless there 
is still a long way to go. Displaying graphics 
remains a problem, in that TVs and most 
monitors cannot cope with real high- 
resoiution graphics of 1,024 by 1,024 
picture-points or pixels. Indeed, many 
micros are used with TV sets that are 
incapable of displaying even the limited 
resolution they are capable of generating. 

However, even higher display 
capabilities should shortly become 
common on personal computers, thanks to 
the remarkable new NEC /*PD 7220 
graphics chip. This was runner-up in a 
recent Am rian hard ware- i nnovation-of- 
the-yea r ipetilion, where the winner was 
the IBM Personal Computer. Two of these 
chips are used in NEC's Advanced 
Personal Computer to provide graphics 
resolution of 1,024 by 1,024 pixels, though 
the screen only provides a 640 by 475 pixel 
window onto this. Nonetheless, the display 
still requires 384K of dedicated video 
RAM. Even in these days of decreasing 
RAM prices, this is far beyond the reach of 
the home micro user and hard for many 
businesses to justify. 

A real high-resolution colour display 
needs about a megabyte of RAM, but with 
2 5 6 K - b i t RAM chips on the way, even this 
will become widely available in time. 
Another factor limiting the advance of 
computer graphics is the lack of 
standardisation between machines. A 
comparison of screen displays on small 
micros reveals every standard from 
excellent, as on the Acorn BBC Micro, to 


the truly appalling, such as the Dragon. 
Business micros ought to be more 
homogenous, but in fact are not; even half- 
a-dozen IBM PC look-alikes turn out to 
offer different screen resolutions. Such 
variations limit software portability 
because almost every graphics routine has 
to be rewritten to suit each micro 

The solution, suggested at the American 
ACM Siggraph conference in 1977, is fora 
core graphics system. The idea is similar to 
the idea behind CP/M, where all the 
machine-dependent parts of the operating 
system are collected together in the BIOS, 
Basic input/output system. This, in theory 
at least, is the only pan that needs to be 
rewritten Tor CP/M to run on different 
microcomputers. CP/M of course treats 
the screen display like a primitive Teletype 
terminal, which is why it currently does not 
lead to too many problems with the 
graphics display. 

The Siggraph idea was to gather the 
machine-dependent graphics routines into 
a similar framework called the CGS or core 
graphics system. Applications programs 
would then present a common face to the 
CGS, which would translate their 
requirements to suit the particular machine 
in use. Thus programs could be more 
standardised and software portability 
greatly increased. Digital Research will 
shortly implement the idea in its GKS 
graphics kernal — addition to CP/M. 

Such approaches rep resent a small step 
on the right road, but the computer 
graphics business is by no means settled yeL. 
Systems like the Xerox Star, ICL Perq and 
Apple Lisa are still making pioneering 
advances in business graphics and 
CAD/CAM — computer-aided design and 
manufacturing applications. The moving 
graphics of arcade games such as Atari's 
Pole Position remain a terrible indictment 
of the graphics capabilities of most home 
micros. Beyond these there are computer 
graphics systems which require vast 
amounts of mainframe processing power, 
whether for films like Walt Disney's Tron 
or for more serious applications such as 
modelling or flight simulation for pilot 
training. 

Computer graphics may have come a 
long way in a mere five years, but the 
changes over the next five should be equally 
dramatic. 2] 


PRACTICAL COMPUTING October 1983 


93 


Taking your 
TV for granted 

Do you plug your micro into the first cheap display screen available? A little more 
information could help you get better results, says Chris Naylor 


MOST OF US can hardly remember a time 
when we did not have television to watch 
at home. Now computer users surely look 
back in vague awe to those times when 
output did not go to a screen* 

The TV screen has become so much a 
part of our lives that the way it works 
seems almost to be beneath our attention. 

In some ways the attitude is justified. 
After all, we just want to switch on and 
watch. Given a small, cheap micro we now 
want a cheap display screen. The domestic 
TV is the obvious first choice, but will it 
give good results? Perhaps a different 
model would work a bit better, or maybe a 
special-purpose monitor. The arrival of 
personal computers has been so sudden 
that your usual source of such 
information, the man in the local shop, 
will not know the answers either. 

The cathode-ray tube or CRT is at the 


heart of every screen. The tube itself is 
made of glass, and is evacuated. At the 
thin end there is a heated element called 
the cathode, which is negatively charged 
and emits large numbers of electrons. Left 
to their owm devices these electrons float 
off in all directions . However, further up 
the tube is a positively-charged series of 
plates, which make up the anode* Because 
electrons are negatively charged they are 
drawn towards it* 

By the time the electrons get to the 
anode they are going so fast that they 
cannot stop, so they go charging on and 
hit the wide end of the tube. The wide 
end of the tube is coated with a 
phosphorescent material which glows 
when the electrons hit it, so when the tube 
i$ switched on the wide end glows with a 
sort of blurred light. 

But not everyone wants a tube which 


glows evenly all the time, so there is 
another electrode, called the grid, in front 
of the cathode at the thin end of the tube. 
When this grid is lying idle it has no effect, 
but if you place a negative charge on the 
grid the electrons will not get a sight of the 
positively charged anodes further up the 
tube and so will have no incentive to go 
there. The result is that as the negative 
charge on the grid is increased, the flow of 
electrons diminishes. The glow from the 
bombarding electrons on the wide end of 
the tube diminishes too, and eventually 
ceases altogether when the charge on the 
grid is large enough. 

A glowing tube whose brightness can be 
varied would be fine to light the room but 
not much good as a display medium* What 
is needed is a little more control, so first 
take a ring of electromagnets and place 
them around the neck of the tube to form 
an electromagnetic lens. Typically there 
are three of them and they bring the 
electron stream to a sharp focus as a dot at 
the centre of the phosphorescent screen* 
Electrostatic lenses are also possible. The 
focus control on the CRT adjusts the 
electron lens, and the brightness control 
adjusts the grid voltage* 

To make the dot do something a little 
more interesting there are four plates 
arranged in pairs around the neck of the 
tube. If one plate is charged negatively and 
the opposite plate positively the electron 
beam deflects towards the positive plate. 
As there are two sets of plates at right- 
angles to each other the glowing dot can be 
moved to any point on the screen. 

There is just one more thing to worry 
about and that is the phosphorescent 
coating on the screen. A phosphor carries 
on glowing even after electrons have 
stopped bombarding it. Some phosphors 
g!ow r longer than others, though in general 
the glow does not really last long at all. 
There are three well known phosphors 
which can be used to coat the tube: 
fluorescein, which glows yellow -green; 
quinine sulphate, which glows blue; and 
chlorophyll, w r hich glows red* By using 
any one of them or a mixture you can 
make the moving dot glow in just about 
any colour you want. 





P P 

/ . 

run 

ill i 

rj 


NJ 

/ 1 

5 


ri 

{ 

* 1 

N 


Figure 1. The cathode-ray tube* 

c — cathode. Negatively charged and emits an electron stream, 

g — grid. By increasing the charge on the grid the eiectron stream can be reduced, 
so it acts as the brightness control. 

f — focusing anodes forming an electrostatic fens to focus the electron beam to a 
fine point on the screen; the focus control, if there is one, alters the charge on 
these anodes* 

a — accelerating anode. Positively charged to draw the beam at high speed 
towards the screen. 

X — X plates. Carry an electrostatic charge which deflects the beam from side to 
side. 

Y — Y plates. Carry a similar charge but work up and down, at right angles to the X 
plates. 

e — electron stream. 

p — phosphorescent coating. Glows when struck by electrons; the colour of the 
glow depends on the type of phosphor used. 

Some CRTs use electromagnetic fields rather than electrostatic deflection plates 

to control the electron beam, but the basic principles are the same* 


94 


PRACTICAL COMPUTING October 1983 


VDUs and graphics 



Figure 2, The oscilloscope screen. 

Using only one input to control the Y 
plates only allows the dot to be driven 
up and down, which is not very useful. 
Using the atuomatic timebase on the 
scope, the dot can be steadily driven in 
X as well as Y to show the entire 
waveform plotted against time. If the 
interval between flybacks is the same 
as the time taken for one complete 
cycle of Y input then a complete 
waveform can be viewed. 

With a device like the CRT available, 
why not stay with it? It's simple and fairly 
cheap. It can draw its dot anywhere on the 
screen, so surely it can handle the output 
from a computer. You just have to put a 
couple of digital-to-analogue converters 
on your computer to provide the X and Y 
inputs and you can drive the dot anywhere 
on the screen you like. This is what a 
vector scope does: it can draw anything, 
anywhere just as fast as the computer can 
send the X,Y data. 

The snag is that the glow from the dot 
does not last very long, so you have to 
write a program to drive the CRT in X,Y 
and then put that program in a loop so that 
it keeps on driving the CRT in X,Y. If it 
does so fast enough, the eye will be 
deceived into thinking that it is viewing a 
stable, permanent image. 

The speed at which the image must be 
redrawn depends on the flicker- fusion rate 
of the human eye, which is typically 
around 12 cycles per second. For a 
computer that is not very Fast at all, but 
you do have to keep on doing it. Faster still 
is better, and to be on the safe side you 
might try doubling the rate to 25 cycles per 
second. Certainly, below 12 cycles per 
second the image will start to flicker in a 
fashion beloved of stroboscopic lighting 


Screen test in Apple Basic. 

18 ft E m : PRACTICAL COMPUTING SCREEN TEST 

H N a UCH * 40: CU = 20: REM :CH IS NO- OF CHARACTERS HORIZONTAL* CU IS C 
hARACTERG uerticallv 
15 REM ; CHECK FULL OUTPUT 

IS HOME zm = “CHECK FULL OUTPUT": GOSUB 1009 
20 TEXT : HOKE : INUERSE 
3u FDR I = W TO CH * CU 
40 PRINT SPCC H >* 

53 NEXT 

55 COSUB 1000 

60 REM : CHECK SCREEN SHAPE 

65 HOME zm = "CHECK SCREEN SHAPE GOSUB 1800 
70 HGR 

83 U = 159:H = 279: REM :H IS HORIZONTAL AND 0 IS UERTICAL 
85 R = U ✓ 4 
00 hCOLuFf 3 

luu HPLQT 0,0 TO H*0 TO H*U TO TO 3,0 

101 HPLQT H ✓ 2*U ^ 2: FOR I = 0 TO 6-3 STEP ,04: HPLOT H ✓ 2 + R * COS 
a^U / 2 + R * SIN Cl): NEXT : REM ;THIS DRAHS A CIRLE IN THE CENTR 
E OF THE SCREEN RADIUS ft 
135 UUSUB 1008 

110 REM :TEST LON FREQUENCY RESPONSE 

115 HOME :m = "CHECK LON FREQUENCY RESPONSE": GOSUB 1638 

128 TEXT : HOKE 

130 NORMAL : PRINT SPC< 20)* 

140 FOR I = H TO CU / 2 

158 INUERSE 

ISO PRINT SPCC CH>; 

170 NORMAL 
100 PRINT SPC< CH 
190 NEXT : PRINT 
105 GOSUB 1000 

200 REM :TEST HIGH FREQUENCY RESPONSE 

205 HOME stt$ a "CHECK HIGH FREQUENCY RESPONSE H : GOSUB 1008 
210 HSR 

220 FOR t = H TO H - H STEP 2 
240 HCOlOR= 3 
250 HPLQT I *0 TO I*U 
268 HCOLGft= H 

278 HPLOT I + H*0 TO I + H*U 

280 NEXT 

285 GOSUB 1800 

298 GOTO 15 

1000 UTAB 22; PRINT Hi: PRINT "PRESS ANY KEY TO CONTINUE "s: SET At: RETURN 


Figure 3. Interlaced scanning. 

An interlaced scanning pattern for a 
seven-line system. Solid lines are drawn 
on the screen and scanned from left to 
right. Dotted lines are not drawn on the 
screen and represent flyback paths. In 
the first scan the odd-numbered lines 
are drawn; in the second scan the even- 
numbered lines are drawn. The diagonal 
flyback from the end of line 6 to the 
beginning of line 1 and the vertical 
flyback from halfway through line 7 are 
field flybacks. The horizontal flybacks 
are line flybacks. In the 625-line U K. 
system 312.5 are covered in the first 1/50th 
of a second and the remaining 312,5 
covered in the next 1/50th of a second. 


but not from side to side. Movement in the 
X direction is achieved automatically by 
the scope itself, and is usually called the 
timebase. 

Suppose that you wanted to look at an 
image of a 1 ,000Hz audio tone. You place 
this signal on the Y input of the scope and 
the dot moves up and down 1,000 times 
per second, which is much too fast to 
detect by eye. However, if you slowly move 
the dot in the X direction at the same time 
the dot marks out the curve of the 1 ,000th 
wave being input. If the dot moves right 
across the screen 1 ,000 times each second, 
yhou would see one complete cycle of the 
input tone on the screen. 

From a computer person's point of 
view, the oscilloscope illustrates two 
important points: the automatic 
generation of an X input to sweep across 
the screen, and a very rapid flyback to the 
(continued on next page) 



specialists. A rate around the flicker- 
fusion rate can be very unpleasant, and 
can even cause fits. 

As you are using your computer to drive 
the screen you cannot use it to do anything 
else — it is tied up displaying things. The 
answer is to have two computers. One 
drives the vector scope and the other 
carries out any other work, occasionally 
passing new plotting data through to its 
partner. In fact, if you buy a vector- 
plotting screen it will have, in effect, a 
second computer inside it to hold the 
plotting data that your computer gives it 
and to drive a CRT over and over again 
with that plotting data. With a good 
internal computer a vector scope can 
produce a very high-quality image, albeit 
at a very high price. 

Oscilloscopes are built round a CRT 
which can receive only a Y input. That is, 
it can move the dot up and down the screen 


PRACTICAL COMPUTING October 1983 


95 


VDUs and graphics 


(continued from previous page) 
starting point so that the process can begin 
all over again. Using these methods il 
becomes possible to draw a two- 
dimensional picture on the screen using 
only one input rather than having to drive 
the screen in both X and Y. 

At this point we come to television. The 
devices I have talked about so far can only 
draw things on the screen that can be 
represented as line drawings* But 
remember the grid and the way that it 
controls the brightness of the dot. If one 
input is fastened to the grid, the brightness 
of the dot can be varied at will* The dot is 
moved rapidly in both the X and Y 
directions so that it covers the entire screen 
in a very short time, a technique known as 
raster scanning. British TVs draw 625 lines 
25 times per second so that a whole screen 
picture is drawn at twice the flicker-fusion 
rate. To make the picture appear even 
more stable the scan is interlaced: it is 
drawn in two passes, each lasting I /50th 
of a second* In the first pass all of the odd- 
numbered lines are drawn, and in the 
second pass all of the even-numbered lines 
are drawn — see figure 3. 

To synchronise an incoming TV signal 
with the TV set the signal includes some 
control pulses which set up the correct line 
synchronisation, or horizontal scanning 
and flyback, and frame synchronisation, 
or vertical scanning and flyback. In 
between these control pulses, in periods 
lasting just l/15,625th of a second, comes 
the picture signal proper in ihe form of a 
burst of activity during which a varying 
voltage controls the grid on the CRT to 
vary the brightness of the spot at any given 
instant — see figure 4* 

It is this video input which drives the set* 
The voltage level controls the brightness of 
the spot: a high voltage extinguishes the 
spot to give black on the screen, and a low 
voltage makes it bright, giving white* In 



Figure 4. Video input to a monochrome TV* 

One tine is drawn every 1/1 5,625Hz of a 
second. The first part of the video signal 
is a high-voltage line-synchronisation 
pulse, followed by a slightly lower 
voltage corresponding to a black tone, 
during which the flyback occurs. The 
signal proper then follows. A synch- 
ronisation pulse initiates the next line 
flyback and another line is drawn. A 
similar method is used at the end of each 
frame scan to initiate a frame flyback. 



The vertical lines on the broadcast test 
cards are actually sine waves. To display 
336 black-and-white vertical bars in each 
line scan of 1/15,626Hz of a second 
requires a bandwidth of 336 x 15,625 Hz, 
or 5.25 MHz* If your computer tried to send 
336 black and white dots to each line it 
would almost certainly generate a square 
waveform. It could be approximated by a 
single sine wave of 5.25MHz, but not very 
welt. The sharp edges of the square wave 
need higher frequencies to fill in the 
corners accurately. If the square wave has 
a frequency f, it will also generate sine 
waves at 2f, 4f and so on. It wilt expect, in 
this example, a bandwidth of 10.5MHz if 
you try to generate a screen picture 672 
pixels wide. 


the early days of TV the system worked the 
other way around. 

In a perfect world every TV set would 
display a perfect picture, but in reality 
there are all sorts of disturbances in the 
incoming signal. Such unwanted 
information in the signal is called noise. 
The most common type of noise consists 
of high-voltage spikes which should not be 
there. With the old system they showed as 
a white spot, and early TV sets were 
plagued with a snowy appearance due to 
noise. The black spots produced by the 
more modern system are much less 
noticeable* 

In normal TV reception the video signal 
is used to modulate an ultra-high- 
frequency carrier wave which is then 
broadcast. This UHF signal is picked up 
by an aerial and demodulated in the set to 
recover the original video signal. 

If you want to drive an ordinary TV set 
from a computer you need a UHF 
modulator inside the computer to make 
the signal look like the normal broadcast 
TV signal. Since the computer's output 
does not have to be broadcast, it is clearly 
a waste of time to modulate the signal and 
then demodulate it again. Specialised 
monitors and some TV sets have a video 
input which will accept an unmodulated 
signal. 

A computer drives the screen via a 
specialised collection of chips. The 
(continued on page 99) 



Figure 6* The shadow mask tube. 

The shadow mask colour tube has three guns all angled inwards. All three electron 
beams meet at a single point so that they can be focused and deflected as one by 
arranging the controlling electromagnetic fields to act at this point also. Directly 
before the phsophorescent tube surface is the shadow mask, a sheet with 
thousands of tiny perforations. All three beams pass through each hole in the 
mask, and so for each hole there are three dots of phosphor on the surface of the 
tube — one red, one green, and one blue — arranged exactly so that the beam 
from each gun hits exactly the dot that belongs to it. By controlling the output from 
each gun an impression of any colour can be formed at any point on the surface of 
the tube. Unlike the monochrome tube the beam cannot really be directed to any 
point on the surface, but only to those points corresponding to holes in the mask. 
On black matrix screens each individual dot of phosphor is surrounded by an 
opaque black ring which improves the colour definition. The main exception to this 
general arrangement Is the Trinitron tube which uses a system of vertical slots in 
the mask rather than individual holes. The Trinitron method is said to give a 
brighter picture. 


96 


PRACTICAL COMPUTING October 1983 



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• Circle No. 163 

PRACTICAL COMPUTING October 1983 



VDUs and graphics 



Figure 7. Allocation of bandwidth in broadcast TV, 

In a colour broadcast the luminance or brightness information is transmitted in the 
lower frequencies. Above it is a band centred on 4,43 MHz which contains the 
chrominance or colour information, followed by a very narrow band centred on 6MHz 
which contains the sound information. Because of the way a TV picture is 
transmitted the overlap of luminance and chrominance is not usually serious. In the 
overlap area the luminance signal tends to occur in clumps, and so does the 
chrominance signal, and these clumps tend to be in different places within the 
overlap area. But your computer may not be quite so well behaved as this, if it 
generates luminance signals over about 4MHz they are likely to be interpreted as 
colour information, and at 6MHz they may be interpreted as sound, A screen width of 
over 500 pixels or thereabouts may give problems with some colour TV sets if the 
Input is to the aerial socket. Using an RGB input bypasses the problem because the 
signal does not then have to be decoded by the set. 


(continued from page 96) 
i standard signal formats for driving TV 
sets are so well known that there really is 
no reason for the video generator to 
produce a bad signal. Yet you will not 
always get a perfect picture: for instance, 
if the line and frame synchronisation is 
wrong you will get a complete mess. The 
problem is too clear-cut to be likely to 
arise, but you can still find your picture is 
less than perfect without being a complete 
disaster. 

In a monochrome set bandwidth and 
resolution dictate how much detail you 
can see. The Apple II In Hires mode will 
draw 279 dots on one line horizontally, say 
a succession of bright pixels and dark 
pixels — 139 bright pixels in all. This 
pattern is roughly equivalent to a wave 
going up and down 139 times. It has to do 
i so within the l/15,625Hz of a second it 
takes the line to cross the screen, so the 
frequency of the signal is 2.17MHz, Any 
set should be able to cope with a 
bandwidth like this. 

Broadcast test cards have a series of 
vertical gratings from which you can judge 
the bandwidth of the set. The highest 
frequency, corresponding to the finest 
grating. If your set can resolve the lines on 
the finest grating then its bandwidth is 
5.25MHz at least. 

There is an important difference 
between TV test cards and a row of 
computer generated dots. The gratings are 
not real, vertical bars but are actually sine 
waves — they do not start and stop with a 
sharp edge. The computer’s pixels do have 
sharp edges, and this raises the bandwidth 
requirements. The Apple Hires dot is a 
square wave which requires a w r hole series 
of higher-frequency sine waves to 
represent it accurately. 

To fill in the corners with a frequency 
twice that of the basic signal raises the 
bandwidth to 4,34 MHz for good graphics 
— see figure 5. Doubling the frequency 
again brings the bandwidth to 8.69 MHz, 
and at this point, the bandwidth 
requirements start to exceed the 
capabilities of most domestic TV sets. The 
broadcast frequency allocations allow 
only 8 MHz per channel, so that is all a TV 
set normally has to cope with. Purpose- 
made monitors can have band widths of, 
say, 24MHz, which is easily enough for 
anything the Apple might produce. 

Working out your bandwidth 
requirements from your micro’s high- 
resolution graphics mode can give some 
useful insights into what you really need 
from your screen. You can then go on to 
look at the advertised bandwidth of 
monitors or, in the case of a TV set, tune 
in to a test card to see the likely bandwidth 
it will accept. 

The next group of things which can go 
wrong hinge on the nebulous concept of 
quality. A TV picture is a very boring 
thing technically. Broadcasters know that 
most people have mediocre TV sets and 
they transmit easily displayed signals to 
match them. Computers are different; 


they can send anything to the screen, and 
the demands they make on it are that much 
higher. 

Switch on your computer and display 
some text, tuning the TV monitor to give 
the best possible display. Now display the 
same data using inverse characters and see 
what happens. Ideally it should be as clear 
and neat as before, but it may not be. The 
shape of the text may change, smearing 
slightly to the right* and if you display half 
a line of inverse characters the second half 
of the line may appear blacker than the 
rest of the screen, as If the bright inverse 
patch had cast a shadow. 

TV sets are not usually called upon to 
display solid patches of maximum 
brightness, and your set’s power supply 
may not be quite up to the job. The result 
is that after showing a block of maximum 
brightness the voltages in the set start to 
sag producing a reduced level of 
brightness immediately afterwards. 
Inverse text w r ritten all over the screen is 
most taxing of all. If anything will make 
the screen sag that will. 

You may also notice little black dots all 
over the place. The modern system of 
having a high voltage on the video signal 
for black and a low voltage for white is 
fine for suppressing the effect of noisy 
spikes as long as the basic background is 
dark. If the screen has a white background 
the noise really shows badly because now 
you can see the black noise dots. If you 
want to use inverse a lot you should try to 
find a monitor that works the opposite 
way round. 

Most people use a colour TV set for 
viewing nowadays, and they often use the 
same set with their computer. A colour TV 


tube is exactly like a black-and-white one, 
except that it has three of everything. In a 
way, it even has three screens to give red 
green and blue phosphorescence. 

Any problems with colour sets almost 
always arise from the methods used to 
code the colour signals. Figure 7 shows 
how the British PAL system of colour 
transmission works. Within the 8MHz 
bandwidth allocated to a single broadcast 
channel, the bottom half of the bandwidth 
is taken up by the luminance or brightness 
information, with around 4MHz devoted 
to the chrominance or colour information 
and a very narrow band to carry the sound 
signal. Black-and-white sets only pick up 
the luminance information, so colour 
signals can be used by everybody, 
whatever type of set that they have. 

The luminance information must not 
exceed about 4MHz — if it does, it may be 
misinterpreted by a colour set as 
chrominance information. Next time you 
watch TV look out for high-frequency 
luminance information which is 
misinterpreted in this way. The fine detail 
of tweed clothing often causes problems, 
so people rarely wear tweeds on TV. 
Bright objects arc also problematical. The 
reflection from a gold candlestick, for 
instance, can produce a very high- 
frequency edge in the picture which is 
mistaken for colour information to 
produce a sudden, vivid splodge of colour. 
If the object is moving to the left the 
problem may be even worse as it causes a 
Doppler effect which pushes the frequency 
even higher. 

What bandwidth do you really need? 
Push 8MHz into a colour TV and the 
(continued on next page) 


PRACTICAL COMPUTI NG October 1983 


99 


VDUs and graphics 


Guide to buying a TV 
or monitor 

1. Work out your bandwidth 
requirement. If W exceeds 4MHz to draw 
a row of 500 pixels in high-resolution 
graphics then you cannot safely use a 
normal colour TV unless it has an RGB 
input. You can use a black-and-white 
set, or you can buy a high-resolution 
colour monitor. An SO-column output 
will normally require too high a 
bandwidth for a colour TV. 

2. If you decide to use a normal TV try 
to get one with an RGB Input rather 
than using a UHF modulator to feed 
into the aerial socket. 

3. Always ask to see a test card 
displayed on a set — you should be 
able to resolve the finest of the vertical 
bars on the card, corresponding to 
5.25MHz bandwidth, 

4. If possible, try out the set you are 
thinking of with the computer you intend 
using. Test it with high-resoiution 
graphics and 80 column output If you 
have it. Also try it with inverse text and 
draw blocks of maximum brightness. 
Look for distortion in the shape of the 
picture. 

5. If you can, buy a set with Prestei or 
Geefax on it. Displays on these 
channels are very similar to what your 


computer may send to the set- if it 
cannot cope with teletext it will 
probably not do very well with computer 
output. 

6. If you feel you can live without 
colour, then a black-and-white portable 
makes a very good buy and you will not 
be plagued by cross colour effects. 
However, the power supply may be 
rather light, causing distortion on 
inverse text. 

7. The safest and most expensive 
choice is a purpose-built monitor with 
14MHz bandwidth or more. The colour 
of the screen phosphor for a mono 
monitor is a matter for personal taste. 

8. The next safest choice is a black-and- 
white portable. Look at a test card on it 
and check its behaviour with inverse 
display. Try to get one with a video 
input on it, 

9. A colour set with RGB input on it and 
one of the information channels is 
ideal. It should not give any problems 
unless you want very high resolution, 
but try it with your computer anyway. 

10. The most difficult item is a cheap 
colour TV with only the aerial socket as 
input. A high-resolution display or an 
80-column card is very likely to send it 
haywire. If you are thinking of buying 
one check it out very, very carefully 
first. 


{ continued from previous page) 
picture will really break up. It may even be 
so bad that it invades the bandwidth 
normally reserved for sound and your 
Hires graphics finish up coming out of the 
loudspeaker. If your computer is causing 
this cross-colour effect then there is not 
much you can do about it . All that can be 
said is that the computer manufacturer 
ought to have designed the TV output 
better. 

If you would be happy with a 
monochrome picture try switching the set 
to monochrome and the disturbance may 
go away. All sets have colour- killer 
circuits so that if a black-and-white picture 
is being received it is not spoilt by colour 
fringing at the sharp edges of objects, 
where a high-frequency luminance signal 
exists. The colour- killer circuits are 
normally switched in when the set detects 
an absence of the chrominance 
information which normally occupies the 
higher frequencies. But any high 
frequencies generated by your computer in 
the luminance band may fool the colour- 
killer circuits into thinking there is some 
colour there. In that case your picture 
bursts into a glorious display of unwanted 
colour as everything is turned on for you. 

The other problem which can arise with 
colour comes from the different broadcast 
standards around the world. All British 
TV sets use the Pal standard. In France 
they use Secam, and in the U.S. they use 
NTSC, So make sure you buy a computer 
with a Pal output otherwise it will not 
work with your British TV. 

If you wanted to set up a small business 
you could go out and buy in a lot of black- 
and-white portable TV sets that nobody 
else wanted, remove the loudspeaker and 
the aerial socket, add a video input socket 
and sell the end-product as a perfectly 
adequate computer monitor. I am not 
suggesting that this is what monitor 
manufacturers actually do, but a monitor 
is really just like a monochrome TV. How 
good a picture it gives depends on how 
well it has been designed and built. When 
buying a monitor you must, if possible, 
see it in action before signing the cheque. 

In theory a monitor will be better than a 
TV set for displaying computer output. 
The whole thing should be better 
engineered to start with and can make use 
of the fact that it never has to handle a TV 
signal. The bandwidth can be very high — 
up to 24MHz in some cases — and because 
the screen does not have the dot-matrix 
pattern of the colour tube it will be capable 
of revealing this greater detail. 

Do your bandwidth sums again: 24MHz 
gives a frequency of 1 ,536 per line, so the 
set could resolve a basic 3,072 pixels. But 
remember that it will still be working at 
625 lines vertically, so you will have nearly 
four times the resolution in the horizontal 
direction as in the vertical direction. 

At 14MHz you can resolve about 1,500 
pixels, around 20 pixels for each character 
on an 80-column output. Divide by two to 
fill in the corners on square waveforms 


and you have 10 pixels per character. 
Because the monitor uses a video input, 
rather than relying on an add-on UHF 
modulator, the picture quality will be 
better than a TV anyway so it only remains 
to test the monitor to make sure that it is 
not doing anything horrible. 

To test a screen connect your computer 
to it, using video/ RGB input if possible. If 
you have to use an aerial socket use 
shielded coaxial cable because the UHF 
modulated signal is very susceptible to 
losses. Keep the cable as short as possible. 

Display a screen of solid white. For 
instance on the Apple's 4(Tby-20 text screen 
enter: 

FOR 1 = 1 TO 40*20: PRINT SPC(1);;NEXT 
to check that the picture is rectangular at 
full output. Then switching to high- 
resolution graphics enter: 

V = 1 59: H = 279: REM: V IS VERTICAL 

PIXELS, H IS HORIZONTAL 

HGR 

HPLOT 0,0 TO H,Q TO H,V TO 0,V TO 0,0 
This is to draw a thin, white border on an 
overall black background and allows you 
to check that the screen shape remains 
good at low output. Go back to text again 
and enter: 

NORMAL: PRINT SPC(20); 

FOR 1 = 1 TO 10 
INVERSE 
PRINT SPC{40); 

NORMAL 
PRINT SPC(40); 

NEXT 

This draws a series of solid bars of white 
alternating with black, each extending 
halfway across the screen. At the middle 
of the screen, where a white block ends, 
look for a darker than usual black band 
following it. Is it darker than the black 


band preceding white on the next line 
down? If it is, it shows that the low- 
frequency response of the set — the extent 
to which the power sags after displaying a 
solid patch of white — is not as good as it 
should be. On a normal TV the same effect 
is sometimes introduced deliberately 
because it can appear to sharpen the image 
up a little. 

Now go back to high resolution again. 
Enter: 

FOR I s 1 TO H - 1 STEP 2 
HCOLOUR = white 
HPLOT 1,0 TO I , V 
HCOLOUR = black 
HPLOT 1 + 1,0 to l + 1,V 
NEXT 

to draw a series of vertical black-and- 
white bars over the surface of the screen. 
If there are H pixels per line, the high- 
frequency response is H/2 cycles per line 
or H*7,812Hz. 

IF the set performs these tests without 
trouble then it is a fairly safe buy. If you 
want to examine it further using broadcast 
test cards you will find one transmitted on 
Channel 4, Q 


Health warning 


Having read this article, you may 
feel tempted to try messing around 
inside your TV set. DON’T DO IT! If 
you were not sure how to do it 
before then you do not have 
enough knowledge to poke around 
inside a TV set. A TV contains a 
live chassis, and the tube usually 
works at tens of thousands of 
volts. It is easily the most 
potentially dangerous device in the 
home. 


100 


PRACTICAL COMPUTING October 1983 





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PRACTICAL COMPUTING. October 1983 


101 




Multi-million 
dollar industry 

John Lewell assesses the computer graphics business. 


IT starts with a distant view of the galaxy, 
then enters the solar system, approaches 
Earth, descends through the atmosphere 
and ends up exploring the retina of an 
insect’s eye. It is the ultimate zoom, a 
computer -graphics device beloved of a 
number of film makers. 

The computer-graphics industry itself is 
becoming so huge that you have to step 
back a long way before you can fit it all in 
the picture. It is estimated by Frost and 
Sullivan that the industry will be worth 
SI 4.5 billion a year by 1990. 

The scientific uses of computer graphics 
are many and wondrous, and without the 
new imaging techniques much scientific 
research would grind to a standstill. 
Computer graphics are used for plotting the 
paths of particles in high energy physics; 
for designing new drugs; in genetic 
engineering; for cartography; for en- 
hancing the images sent back by space 
probes; for representing bone structures 
prior to surgery; for designing semi- 
conductor chips; for modeling abstract 
theories; and for showing the effects of 
stresses on man-made objects. 

Computer-aided design comes into a 
separate category, as it is specifically 
concerned with product design. CAD 
systems are used by engineers, industrial 
designers, architects, aerospace and car 
manufacturers, and by printed-circuit 
board designers, 

CAD/CAM, the extension of computer- 
aided design, carries the process through to 
computer-aided manufacturing. With it a 
product may be manufactured auto- 
matically as soon as the design has been 
completed by linking the CAD system and 
the numerical-control machinery that is 
used in milling and molding processes. 

All the specifications for the new product 
are held in a database while a three- 
dimensional model of the product is 
constructed by the designer on an electronic 
graphics display. When everything is ready 
and the computer has made all the 
analytical tests, modified information is 
passed to numerical control where lathes, 
mills, drills and molds are automatically set 
to the new specification. Presto! Your 
industrial robots have made a new ashtray, 
or space shuttle or a better mousetrap. 

The category loosely labelled ‘‘business 
and presentation graphics 1 ’ is the area of 


most interest to person a I -computer users, 
and it is the one on which we shall be 
concentrating. Few companies in the 
business-graphics area are more than 10 
years old, most of them are more like 10 
months old. Office graphics is very much 
the younger sister to scientific and CAD 
applications. 

Within this enormous category you can 
find some very strange bedfellow's. An 
animated ABC Television logo and an 
analytical paper graph showing the sales 
performance of General Motors have little 
in common other than the fact that both 
images were generated on a computer. 
Business and presentation graphics may 
exist in electronic form, on video tapes and 
discs, and in computer memories. Or they 
may be placed onto hard copies — 
photographic Him, paper, or plastic. 

Each of the three main computer- 
graphics categories contains a multitude of 
different stories but the third one, business 
and presentation graphics, is the most 
varied of all. The entire range of computing 
power from the massive Cray I down to the 
Sinclair ZX-S1 can be applied m this 
category. 

As microcomputers become more 
powerful they begin to play a larger role in 
all aspects of business and presentation 
graphics. Whereas research scientists and 
motor-car designers continue to rely on 
their mainframes and super-minis, the 
business user is finding that his other 
graphics needs can sometimes be met by 
less expensive systems. The most effective 
graphics hardware is currently to be found 
in the mid-range of computers, though you 
will be w r ise to keep one eye on those 
micros. The future may well belong to pint- 
sized processors. 

Moving closer to the subject, you can see 
the industry in greater detail. Looked at in 
terms of products rather an activities, there 
are three main types of graphics display: 
the direct-view storage tube or DVST, the 
stroke- refresh display, and the raster- 
refresh display. You are more likely to 
encounter the stroke-refresh type in 
engineering and architectural design 
applications, and the raster- re fresh type in 
business and presentation graphics. 

The DVST was developed in the late 
1960s mainly in an effort to bring down the 
cost of graphics displays. It forms an image 


using an electron beam that moves more 
slowly than in other devices. The image is 
stored temporarily on a mesh in which the 
phosphor is embedded. For simple 
applications, the DVST is still very popular 
since it does not require the expensive 
additional ciruitry known as a refresh 
buffer. 

Line-drawing displays date from the 
mid-1960s. They show line drawings by 
instructing the electron beam to connect 
end-points which have been digitised into 
the computer memory. The display 
processor and display-buffer memory then 
assemble the picture by repeatedly passing 
instructions to the electron gun which 
writes the picture on the screen. 

Raster-graphics technology is closer to 
the operation of a normal TV set. Picture 
information is stored in the buffer in terms 
of picture elements or pixels. The 
horizontal scan lines of the display are now 
composed of these individual picture 
elements, the whole raster being a matrix of 
pixels. This technology burst into 
prominence in the mid-1970s and is 
destined to become the major type of 
display. It appeared late on the scene 
because far more computing power is 
required to calculate the intensity and 
colour values of millions of pixels than to 
calculate just the end-point positions of 
vectors in a line-drawing display. 

To judge the resolution of a raster 
display you can simply count the number of 
pixels; a matrix of 512 by 512 is considered 
average. However, when a picture is split 
up into discrete square elements there is a 
loss of resolution especially in representing 
diagonal lines, which tend to look like 



Polaroid’s VideoPrinter Model 8 colour 
film recorder. 


102 


PRACTICAL COMPUTING October 1983 




VDUs and graphics 



The Gradis 2000, with the operator holding the cursor which is used for digitising. 


staircases, A software technique called 
anti-aliasing has been developed to smooth 
out the jagged lines. In it the intensity 
values of pixels that are adjacent to areas of 
solid colour are adjusted to create the 
illusion of smooth edges. 

The main difference between vector and 
raster displays is the ability of the raster 
display to show solid areas of colour, 
something which is essential in business 
graphics. Industrial designers, too, are 
becoming increasingly interested in raster 
systems because they can simulate the 
actual appearance of a product by solids 
modelling. Another plus for the raster 
approach is that the screen never flickers, 
however much visual information is 
crammed on to it. Vector displays suffer 
from this complaint because the refresh 
time can easily be exceeded by the time 
taken to write the whole image. On the 
other hand, raster systems rarely match the 
resolution of good vector systems. 

“Interactive” is a word which one often 
finds associated with computer graphics. 
The idea of a human being interacting with 
a computer-driven display was inherent to 
the very first step taken by Ivan 
Sutherland's Sketchpad program in 1963. 
Since then, the technology has been refined 
to a point where even voice recognition has 
a role to play, though most interaction is 
still through touch devices. They are used 
both for inputting and controlling the lines, 
dots and shapes that comprise the picture. 

Interactiveness comes at many levels. It is 
possible to address an electronic image in 
machine code via an alphanumeric 
keyboard, but no one should really describe 
that as being truly interactive. What is 
portentously called the “human/machine 
interface” is dependent on having a 
number of convenient input devices so that 
artists, designers and other ordinary 
mortals can make pictures with the 
computer. Among the devices available to 
input or control picture information are: 
data tablets and stylus, touch-sensitive 
screens, light-pens, keyboards, joysticks, 
tracker balls, control dials, function 
switches, hand cursors and mice. 

A mouse is a small hand-held locator 
device that can roll across a flat surface 
while keeping track of its own position. 
Two sets of tiny wheels set at right -angles in 
the base of the mouse register changes in 
movement in two dimensions. The 
instrument is used for locating positions of 
points that are to be entered into the 
computer memory. This process is known 
as digitising. 

Other digitising devices for inputting 
pictures include the hand cursor and the 
stylus and tablet. The hand cursor, like the 
stylus, works in conjunction with a 
sensitive tablet. It has “cross-hairs” to 
indicate the point- positions. Function 
switches are often included on a hand- 
cursor to give various instructions, such as 
Pick or Select. 

Manufacturers have really gone to town 
with data tablets. Sonic tablets, for 
instance, measure the stylus position using 


strip microphones along two adjacent 
edges. The microphones pick up sound 
waves from the tip of the stylus, which 
emits a small electrical spark. Far more 
accurate — and quieter — is the tablet that 
has a grid of wires embedded in its surface. 
The co-ordinates of a point are then picked 
up by the stylus as variations in voltage. Yet 
another method is to use special material 
for the surface of the tablet through which 
electrical pulses can travel at right angles to 
each other. The pulses are emitted at 
regular intervals and so the stylus position 
can always be calculated. 

A graphics tablet is a simulation of an 
artist’s drawing board. Instead of seeing 
the image on the board you see it on a 
screen. Combine the tablet with a stylus 
which simulates a brush or a pen, and you 
really begin to feel like an artist. Whenever 
the stylus touches the tablet, a pressure- 
sensitive switch in the tip signals the 
location. A cursor may appear on the 
screen or, depending on the program, a 
pixel may be illuminated. Move the stylus 
and you get a row of pixels where before 
you had a blank screen. 

Touch sensitive screens are used in some 
systems to give the operator a more direct 
contact with the electronic image. No 
screen cursor is then needed. There are both 
low-resolution and high-resolution touch 
screens, having 10, 50 or even 500 
resolvable positions vertically and 
horizontally. Like the tablet, they work on 
several principles, including both light- 
wave and sound detection. 

Light-pens detect light on the screen by 
means of a photocell located either in the 
pen itself or at the end of a fibre-optic pipe. 
They are more useful as positioning devices 
in line-drawing systems than as mere 
pointing devices in raster displays. To 
position images they require a tracking 
program in the computer software. 

Keyboards are familiar to ail typists and 
programmers. The chord keyboard, 
however, is a five-button device that is 
played like a midget’s piano. You can 
generate 31 different instructions on it if 


you are clever — but beginners should stick 
to the normal alphanumeric keyboard. 

Joysticks and tracker balls are used for 
scrolling or panning the screen image. A 
joystick is also convenient for tumbling a 
wire-frame or a three-dimensional model in 
space. Control dials and function switches 
help you give instructions quickly and 
efficiently without having to type in more 
precise details on the keyboard. 

The trouble with computer graphics is 
that people still want to carry images 
around with them. They like to look at 
them on the bus or scrutinise them in the 
boardroom, or project them on to a screen. 

Far from decreasing the amount of 
printed material computers are actually 
increasing the quantities of paper and 
photographic products we consume. 

Electromechanical output devices 
convert electronic images into hard copy. 
Both printers and plotters come into this 
category. Plotters draw while printers 
imprint — yet ink-jet printers imprint 
without even touching the paper. 

The cost of electromechanical output 
devices range from a couple of hundred 
pounds for a single-pen plotter up to 
several hundred thousand for a 
sophisticated film recorder. Most of the 
devices have potential applications in 
making presentation and audio-visual 
graphics. 

In film animation you do not have to use 
a film recorder: you can use a pen plotter 
instead. The computer-generated sequences 
for the American TV series “Music in 
Time” were created by taping an animation 
peg-bar on to the paper In a mechanical- 
arm plotter. The computer drawings, all in 
exact register, were later photographed and 
coloured by an optical camera. 

Electrostatic printers are sophisticated 
photocopying machines, and Xerox is the 
leader of the pack in this field. For 
computer graphics they are both fast and 
economical, using either a matrix-writing 
technique or a photoconductive plate at the 
heart of the system. In matrix writing an 
(continued on next page) 


PRACTICAL COMPUTING October 1983 


103 



Multi-million 
dollar industry 

(continued from previous page) 

invisible image is placed on to the paper by 
a electrostatic charge applied by a matrix of 
needles. Liquid toner is then wiped on to 
the paper, and dings to the charged areas. 
In an alternative method, the image from 
an internal cathode-ray tube is transformed 
by a photoconductive plate into an electric 
charge on the paper. 

Laser printers work in a similar way to 
the second electrostatic method, except that 
a laser beam is used instead of a CRT 
electron beam. These machines are very 
fast: the Xerox 6500 CGP prints 180 colour 
copies per hour, and Xerox has a machine 
that can produce 7,000 black-and-white 
charts per hour. Both electrostatic and laser 
can prim in full colour on to a variety of 
media by applying carbon particles in seven 
colours: cyan, magenta, yellosv, red, green, 
blue and black. 

Impact and non-impact plotters tend to 
be relatively low-resolution devices which 
are well suited to providing hard-copies of 
raster images. Impact plotters work like 
sophisticated typewriters in that they use 
ribbons and hammers for printing. Non- 
impact printers work on a variety of ink-jet 
principles, spraying coloured inks on to 
paper without any physical contact between 
the surface being printed on and the jets. 
Non-impact printers are also ideal for 
putting images on to fragile materials. 

Photographic recorders produce slides or 
prints from individual frames, either 
directly from a CRT or by collecting and 
reassembling the picture information. 
When a CRT is photographed directly the 
scan lines will appear in the photograph. A 
photographic recorder, introduced a 
controlled amount of blur into the picture 
so that the lines disappear. Sophisticated 
electronics are needed to match the red, 
green and blue CRT output with the 
response of photographic films. 

Film recorders are similar to 
photographic recorders — but are around 
100 times more expensive. Film recorders 
of this type use a special internal black-and- 
white single-line raster-scan CRT to display 
the image. Its scan is closely co-ordinated 
with the film transport so that the Him 
moves a fraction of an inch after each scan 
line to build up an image. Colour is 
introduced by using a filter assembly, A 
powerful minicomputer analyses the 
image into primary colours and intensity 
values. 

Once you have established what kind of 
hard copy you require, the next step is to 
specify the operating mode. In on-line 
plotting, the machine is connected to the 
host computer by cable. The method is Fast 
and convenient — and expensive too 
because of the computer time involved. 
Off-line plotting makes copies from data 
supplied from storage media such as tapes 


or discs. It can be used with a central hard- 
copy facility, when operators can be 
specially trained in this aspect of graphics. 

System companies take equipment from 
original equipment manufacturers, design 
and build additional hardware, and put the 
whole system together as a package for 
specific applications and markets. They 
may also write or commission special 
software to run on their systems. 
Unfortunately many end-users simply do 
not take the trouble to shop around. If they 
deal with IBM for, say, data processing 
systems, they wait until an IBM salesman 
brings around a new graphics product. The 
alternatives are to spend weeks sifting 
through mountains of information, 
attending lengthy demonstrations, or 
employing a consultant. 

The best approach is to hire a generalist 
consultant. He can suggest specialist 
consultants who will work with you to 
purchase and commission a system. 
Remember that computer graphics is more 
than just a slide-making system. 

The systems of scientific and technical 
graphics, and for CAD/CAM need not 
concern us. The business and presentation 
graphics category contains a myriad of 
systems companies. 

Analytical systems help us to understand 
the output of the computer in graphic 
form; presentation systems produce 
custom-made graphics for business 
presentations. Plenty of overlap exists 
between the two types, but the distinction is 
important. There is a big difference in 
manipulating a billion pieces of data when 
you make a business graph, from merely 
generating a computer image because you 
like the look of it. 

Business graphics are divided into 
analytical and presentation systems. The 
products themselves can be further divided 
into hardware and software solutions. 
Hardware solutions involve purpose-built 
display hardware. Stand-alone systems 
which are usually minicomputer based are 
available in this category and can often be 
hooked into a larger data base. 

The software solution is becoming 
increasingly popular as CPUs become more 
powerful, it involves the generation of 
graphics displays by running sophisticated 
software through a general-purpose 
computer. 

Business users are demanding high 
resolution, ease of operation, speed, and an 
ability to hook into a corporate data base. 
A state-of-the-art device with these features 
will also give good performance per dollar. 

When you increase the resolution of a 
display, for example, you immediately 
meet with the law of diminishing returns. 
As you double the number of pixels on each 
axis you are quadrupling their total 
number. Displays also feature a number of 
pixel layers — or planes — in the z-axis, the 
depth of the picture, and while this is not 
directly related to resolution it effects the 
number of colours that the display can 
handle. 

A new feature that has been introduced 


Business graphics systems 

Apple Business Graphics 

Turns data Into graphs. Telephone 
Apple, Heme! Hempstead (0442)60244. 

Apple Use 

Hard disc-based personal micro with 
powerful Integrated graphing capabilities 
provided by LisaGraph, Telephone Apple, 
Hemel Hempstead (0442) 60244, 

Bit-Stik 

Built around a graphics joystick with X 3 
Y and Z directions, links to an Apple II, 
Telephone Bobocom, 01-263 3388. 

Boxer 

A three-dimensional solid-modelling 
facility which works in conjunction with 
DOGS, a geometric-modelling Drawing 
Off i c e G raph i cs Sy ste m , o ri g i na I ly 
developed at the University of Leeds. 
Telephone Pafec, Nottingham (0602) 
292291. 

BFS Business Graphics 
In effect a word processor for business 
graphics, It interfaces to most popular 
printers and plotters and runs on the 
IBM PC. Imported from Cambridge, 
Massachusetts by Pete & Pam 
Computers. Telephone: Rossendaie 
(0706) 227011. 

Context MBA 

Powerful spreadsheet with limited text 
entry, database and graphics facilities 
integrated together. Available for the 
IBM PC and Hewlett Packard Series 200 


by Raster Technologies, a Massachusetts | 
company, is a graphics display system that 
allows you to put the image on to either a l 
512-line monitor or a 1024-line monitor. , 
With its Model Qne/40 you can also select 
the full display on the higher-resolution 
sc reen o r w i n do w i n t o t he i m age mem ory i n 
the 512 mode. The product can be 1 
described as state-of-the-art because it 
meets the requirements of high per- 
formance, versatility and relatively low ' 
cost. 

Good software is the key to good 
computer graphics. The quality of the end- | 
product — the picture or graph — is 
entirely shaped by the ability of the 
software to help you deliver an appropriate 
image. 

Graphics software packages are a major 
growth area of the industry. They are 
available for mainframes, minis and 
micros. But people in the mid-range of 
quite expensive stand-alone mini-based 
systems may well find themselves in a son 
of no-maiTs land within a few years. 

Mainframe software is so powerful that j 
once you have seen the results you will fnd 
it hard to settle for anything else. Neither is 
it strictly true, as some stand-alone 
suppliers claim, that graphics packages tie 
up mainframe resources at the expense of 
other applications. At the lower end of the 
market, as micros become more powerful 
very sophisticated software Is being written 
for them. 

The big breakthrough in software 
packages has been the improvement in 


104 


PRACTICAL COMPUTING October 1983 


VDUs and graphics 


Model 16, Telephone The Software 
Rental Bank, Leighton Buzzard {0525) 
373440, or Hewlett Packard (0344) 

773100. 

Dataplot 

Business graphics package which can 
interface to the Supercalc spreadsheet 
and to Graph text, a word-slide 
generating package* Runs under CP/M 
and MP/M. Contact Graf ox, Oxford (0865) 
242597. 

dGraph 

Versatile business graphics package 
which entails minimum programming 
and interfaces with Ashton Tate's dBase 
IL Telephone Fox & Gelter, 01-580 5816. 

Dlcomed 

Computer-based high-resolution colour- 
slide design system aimed at audio- 
visual producers, Dicomed copes with 
text, electronic drawing, digitising and 
freehand drawing* Eidographtcs then 
produces the final slides from your 
floppy discs. Contact Eidographics Ltd, 
47 Marylebone Lane, London WL 
Telephone: 01-486 9479, 

Graforth 

All-singing ali-dancing graphics package 
written in Forth, includes a built-in music 
synthesizer. Telephone SBD Software, 
01-948 0461. 

Graphics Toolkit 

Business graphics package for the ACT 
Sirius, interfaces with Supercalc. 
Telephone ACT, 021-501 2284. 


Graph it 

Simple graph-drawing package for Atari 
micros* Telephone Atari, Slough (0753) 
33344. 

Graphkit 

Graph plotting, curve fitting and 
statistical analysis package for 
Commodore Pets* Telephone 
Commodore Information Centre, Slough 
(0753) 79292. 

Graph 1 n’Calc 

Graph-drawing program with its own 
modest spreadsheet, for the IBM PC, 
Imported from Santa Cruz, California by 
Pete & Pam. Telephone: Rossendale 
(0706) 227011. 

Lotus 1-23 

Spreadsheet with a powerful graphic 
extension built in. Telephone Planning 
Consultancy, 01-839 3143* 

Peachtree Graphics Language 
Interactive graphics programming 
language which runs under CP/M and 
MP/M, and interfaces to 
Peachcalc/Magicalc and 
Peachtext/Magic Wand. Telephone 
Peachtree, Maidenhead (0628) 32711. 

Perq 

Amazing mouse-driven graphics system 
for draughting and CAD/CAM 
applications. Telephone ICL, Infopoint, 
01-788 7272. 

P L Graphics 

Digitising and drawing system based on 


the BBC Model B and suitable for 
schools and small businesses. 

Telephone B S Dollamore, Burton-on- 
Trent (0283) 217905. 

StarGraphics If 

35mm. colour-slide design system based 
on the Apple II micro. Myriad produce 
the final slides from your discs. Contact 
Myriad, 106 Hampstead Road, London 
NW1, Telephone: 01-380 0191. 

Sub-Logic Graphics Package 
For displaying three dimensional scenes 
on a two dimensional display. Telephone 
Pete & Pam, Rossendale (0706) 22701 1 . 

Utopia Graphics Table System 

Provides 64 colours, 40 brush shades 
and pen-controlled editing. 

Vectrix VX Series 

CAD/CAM and business graphics system 
which includes NEC chips and an Intel 
8088, and links to various personal 
computers including the IBM PC, Sirius, 
Osborne and Hewlett Packard and 
Apple. The VX-384 can display up to 512 
colours from a palette of 16.8 million. 
Imported from Greensboro, North 
Carolina by Sintrom Electronics. 
Telephone: Reading (0734) 875464, 

VisiTrend/Plot 

Converts data from VistGalc and other 
Vis! products into business graphics. 
Telephone Rapid Recall, (0494) 38525. 




user-friendliness. This is a marketing 
breakthrough because the people who 
really need graphics are rarely skilled in 
computing. Yet the most sucessful cases of 
business graphics implementation have 
been where hundreds and even thousands 
of company employees have been trained to 
operate a system* No longer is computer 
graphics an arcane and mysterious art. The 
new techniques are available to everyone* 
First-rate graphics software is now 
almost affordable by everyone* VisiPlot, to 
run on an Apple computer, is priced at 
around £177. At these rates, the use of 
computer graphics will become almost 
universal in small businesses and perhaps 


even in the home. 

Word processors can be converted into 
graphics workstations with the addition of 
appropriate software. Writing a software 
package, however, requires highly-skilled 
programmers, The business graphics 
packages offered by Apple Computers 
took 200 man-years to develop — and 
woman -years no doubt. 

The academic interest in artificial 
intelligence is influencing new approaches 
to computer graphics. Eventually even the 
most advanced scientific thought reaches 
the businessman in one form or another* 
One phenomenon of particular interest to 
students of artificial intelligence is pattern 


recognition. We do not fully understand 
why or how we instantly recognise, say, the 
face of a friend in a crowd of people, when 
everyone in the crowd has two eyes, two 
ears and a nose in approximately the same 
places. It prompts the question, can 
patterns be generated and developed to help 
the businessman recognise the friendly face 
of his sales statistics? 

Over the past decade we have survived a 
blitz of multi-image shows which have 
helped pave the way for an appreciation of 
pattern recognition as a business tool* 
Today’s incredible growth of computer 
graphics is both a symptom and a cause of 
this new development of human skills. 


Business graphics 

Our world’s economy, depicted in colourful business 
graphics, looks pretty unhealthy* Today you can see all 
those complex statistics at a glance, arranged for you by 
the computer in graphic format. Gone is the time when 
economists could pretend to be deaf when asked which 
way the wind was blowing. But if charts and graphs 
show us a sorry picture of the world recession at least 
the world of business graphics is booming, at a rate of 
around 70 percent a year* 

Graphics Software, Inc., an Oregon-based business 
graphics company, makes a startling claim, “Mainframe 
quality graphics can now be replicated on your 
mini/microcomputer* “ The claim will bear scrutiny 
providing you read it carefully. The company is not 
suggesting that an Apple II can perform the same service 
as a big mainframe complete with Tell-a-Graf software. 
Rather, it is saying that its product, GSS Plot, will lift 
micro graphics to a new level of flexibility. The software 


will run on most mini and microcomputers, and it is fully 
device independent in regard to CRTs and plotters. 

This particular software package has been designed 
specifically for applications software developers. GSS 
Plot contains all the necessary computer instructions to 
prepare presentation quality line graphs, bar charts, 
scatter charts and other types of display* For example, a 
user need call only four related sub-routines arid supply 
13 parameters in order to generate a complex pie chart. 
Without the GSS Plot subroutines you would have to 
write a 100 lines of code and make all the necessary 
tests before being able to generate similar graphics* 

Since CP/M has become the favoured operating 
system of most personal-computer manufacturers, GSS 
has signed a deal with the GP/M originators, Digital 
Research Inc,, and now offers GSS Plot in CP/M 
compatible form* This co-operation could have a 
significant impact on the future of business graphics, 

(confirmed on next page} 


PRACTICAL COMPUTING October 1983 


105 



VDUs and graphics 


Multi-million dollar industry 




(continued from previous page) 

enabling micro users to add a true graphics capability to 
their machines. Tom Clarkson, president of GSS, says 
that the agreement, "will significantly assist our ability 
to make standardised graphics software available to 
micro and minicomputer users.” 

Another company to watch in this field is Graphic 
Communications (no., of Waltham, Massachusetts, Its 
President, Randall E Wise, is a strong believer in what he 
calls the software solution. He says, "There are 
hardware solutions to stand-alone graphics and there are 
software solutions to stand-alone graphics. We have 
chosen the software solution, currently operating on the 
HP-8587. That concept works on an IBM Personal 
Computer as an application. And powerful 16-bit 
computers are coming afong with very good software, 
which can very neariy duplicate the capabilities that 
other stand-alone systems are offering with their 
hardware solutions”. 

Special hardware is always more expensive than 
general-purpose software. Randall Wise suggests that 
the companies who are offering expensive hardware for 
business graphics will find themselves fighting a losing 
battle on prices. "I don’t know how they are going to 
react to the new software that will duplicate their 
capability for a few thousand dollars." 

Business graphics are often required in slide or 
overhead transparency format. Polaroid instant film 
technology has made a big impact on this market with 
several manufacturers incorporating instant film 
cameras in their systems. Polaroid has several products, 
in particular, the Videoprinters Models 4 and 8. "We can 
now bridge the gap between electronics and film,” says 
James Hartnett, Marketing Manager of Polaroid’s 
Professional Film Products Division. "Previously, film 
had not been appropriately matched in phosphor 
response to proper exposures of red, green, or blue 
levels. In the Model 8 It is possible to optimise the two 
— and get the best result." 

The Model 8 Videoprinter is a microprocessor- 
controlled display-driven device, producing 8in, by lOin. 
instant colour overhead transparencies. “It is very state- 
of-the-art in digital input and information gathering,” 
says Hartnett. The Model 4 is intended for 4 by 5 formats 
and smaller, including the new instant-process 35mm. 
film that Polaroid is launching later in 1982. 

One of the first micro-based graphics systems came 
from Cromemco, a company that is better known for its 
CAD/CAM hardware. The Z-2H graphics system is based 
on the Z-80 chip, and has recently been upgraded to 
include the Motorola 68000. This allows the display of a 
1,000 by 1,000 matrix, putting it just into the high- 
resolution bracket. Cromemco has supported its system 
with two software packages, Slidemaster and 
Fontmaster. With Slidemaster and a graphics tablet a 
user can choose from 75 design functions that are 
displayed on both screen and tablet menus. The package 
is intended for presentation graphics, and includes a 
carousel mode that allows you to call up an image 
sequence as though you were controlling a slide 
projector. Fontmaster lets you design your own lettering 
or special characters such as scientific notation. 

Excellent software for both the Apple II and III has 
been developed by Business and Professional Software 
of Cambridge, Massachusetts. Recent packages from 
this company, marketed by Apple themselves, go beyond 
the presentation graphics of its earlier software. The 
two-diskette package, now called Apple Business 
Graphics, allows you to create colour graphic 


representations of data using English language 
commands. For instance, sales projection data can be 
retrieved from a VisiCalc program and automatically 
displayed as bar, line or pie charts. 

Like the Cromemco system, the Apple Business 
Graphics package can make the computer function like a 
slide projector. It requires the addition of a new product 
called Screen Director, two diskettes that come with a 
Kodak hand-held projector controller, which plugs into 
the game-slot on the Apple. David Solomont, President of 
BPS, says, "Apple Business Graphics allows the user to 
create and store graphic images. Screen Director 
retrieves and displays them on video monitors for 
presentation.” It also lets you create hard copies of a 
whole tray of images on many brands of dot matrix 
printer, including the IDS Paper Tigers, Anadex 9000s, 
Epson MX line and Apple Siientype. The IDS Prism will 
produce hard copy in colour. 

With the low cost of Apple software and the relatively 
high cost of colour slide-making systems an attractive 
solution is to make use of a hard-copy bureau service. 
Comshare has tried out its Target Image Maker on the 
Apple. Users of the system would be able to create 
charts on their in-house computer and then download 
them to a Comshare facility for production of the slides. 
At this point the Post Office takes over, the postman 
brings you the slides in the mail. Perhaps this deflates 



The Apple Business Graphics package makes the computer 
function like a slide projector. 


some of the high-tech magic that surrounds the creation 
of electronic images, but it is also the thinking behind 
the Comerstone/Clear Light Stargraphics operation. 

If business graphics becomes as simple and as 
inexpensive as many experts predict, we shall be knee- 
deep in graphs and charts before the decade is over. 
Manufacturers are already treating the subject as though 
images will be manipulated with the ease of words in 
word-processing. Another name will have to be found for 
this technique, since image processing means 
something quite different — image enhancement. 

Hinting at the shape of the office of the future, 
Hewlett-Packard can now proudly show off its Merged 
Text and Graphics system. This will actually produce 
illustrated business correspondence, among other 
applications. Perhaps we shall eventually be able to 
dispense with words altogether and communicate with 
each other entirely in pictures. This, of course, will only 
deepen the world recession. The left side of our brains 
will be redundant, while the right side will be on strike — 
demanding extra pay for extra work. (3 




I 




| 


106 


PRACTICAL COMPUTING October 1983 




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languages + solicitors + CAD 

106 St Leonards Road Windsor Berkshire SL4 3DD 
Telephone: Windsor 50111 Telex: 23152 MONREF G (Ref 8542) 


• Circle No. 167 


PRACTICAL COMPUTING October 1983 


107 



Geometrical 


THE STANDARD METHOD of plotting lines on 
computer-graphics sytems is very similar to 
the way a pen and paper is used. 

The main difference is that the com- 
puter is a comparatively simple machine 
and can normally only draw straight lines. 
To draw a circle, for example, the com- 
puter has to divide the curve up into short 
straight-line segments which it then plots 
individually. 

Even drawing lines requires a lot of 
software. Anything less straightforward 
calls for a library of routines. Often the 
programmer must start from scratch using 
only .a basic line-plotting routine supplied 
with the system. 

The listing provides a library of useful 
plotting routines written in Basic which 
should run on any machine. Only one 
routine needs to be written to interface the 
library with most line -plotting systems, and 
usually it only needs to be a line or two in 
length. 

The interface routine is at line 1000 and is 
used by all the other plotting routines in the 
library. It moves the cursor from the 
current position to a new position specified 
with a pair of X,Y co-ordinates in the 
parameters. A third parameter is used to 
specify the mode in which the cursor is to be 


In the library it is assumed that only one 
colour is available for the line drawing. 
You could use a global variable to specify 
the colour to be used for plotting if your 
system allows it. The routine at line 1000 
must then use this variable to plot the 
correct colour. 

All the routines, apart from the basic 
plotting routine and the conversion 
routines, need to be supplied with a starting 
position offset XO and Y0 from which 
plotting will commence. The variables TO 
to T9 may be corrupted by the library 
routines and thus should not be used to 
hold global values. 

None oT the routines in the library 
contain line-number references using Goto 
or Gosub statements, apart from line 1000 
for the basic line-plotting routine. You can 
easily relocate the code to different line 
numbers, tT you wish, without changing the 
code itself, provided the Plot routine is on 
line 1000, 

The library should be stored as a single 
file. When a new program which uses some 
of the library routines is to be written, the 
library itself should first be loaded. Unused 
routines may be deleted and the program 
typed in on the keyboard. The program and 
library routines may then be renumbered as 


written for a specific system. Most of the 
other routines in the library call this 
routine. Input parameters are: 

X — - X co ordinate of new position 
Y — Y co-ordinate of new position 
M — mode of plot; 0 to move without 
drawing line, 1 to draw line to new 
position 

Line-plotting routines 

Draw, line 1100. Draws a line between 
two positions. Useful when the two end 
co-ordinates of the tine are known and 
the current position of the cursor is at 
neither of them, input parameters are: 

X0 — starting X co-ordinate 
YG — starting Y co-ordinate 
LI — finishing X co-ordinate 
L2 — finishing Y co-ordinate 

Line, line 1200. Draws a line from a 
position. Should be used when the 
starting co-ordinates and the relative 
position of the finishing co-ordinates are 
known. Input parameters are: 

X0 — starting X co-ordinate 
Y0 — starting y co-ordinate 
LI — increment in X direction for final 
position 

L2 — increment in Y direction for final 
position 


moved. If it is zero the cursor is simply 
moved to the new position. If it is non-zero 
a line is also drawn from the old to the new 
position. The value of the parameter may 
be used to specify the colour and/or 


required before being saved as another file. 

Interface routine 

Plot, line 1000. Plots from current 
position to new position. The only 


Radius, line 1300, Draws radius of a 
circle. Useful when the angle and the 
length of the lines are known rather than 
the X,Y co-ordinates of the end of the 
line. Input parameters are: 


itenslty of the line to be drawn. 

routine in the library which needs to be 

1 xo- 

- starting X co-ordinate 

Geometrical plotting. 

1350 

COSUB 1000 

17 10 

RETURN 




136D 


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10130 

REK 'TLDT" 

1370 

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1730 

Ll^L 


mo 

RCM 

1300 

Y-YO+LSSimm 

174 0 

L2"L 


1 020 

REM <U) J . f 1 . DOULN , DCTCBCR IV 02 

1390 

GOSUB 1000 

1750 

N=4 


HJ30 

REM 

1 40 0 

RETURN 

1760 

REM "RECTA NULL " >X0 

,Y(M_1 ,L2 „ A , 1 

11140 

R EM X X Jf * * X X X X # 5G * X XX X X XX X X XX X XX 

141 0 

REM ''FIGURE 11 , Y0 *L! ,L2 n Nl , 

1770 

T0=A#F 1/ 1 SO 


IQ SB 

REM x Machine dependent code * 


X< ? ) + Y(?> 

1 7ti!G 

Tl-COS( r D > 


1 06 Q 

RErt *»■»*#■»*#*» «****«*» «* XXXXXX 

1420 


1770 

T£=SIN( TO ) 


1070 

rem 

1430 

X-XCNLl#X<Mn 

100 D 

M=0 


1 uno 

REM 

1440 

Y-Y0+L2*Y(Nl > 

1B1 0 

X=*X0 


i m 

RETURN 

14UQ 

GQSUB 1000 

1U2Q 

Y-YO 


1 1 [) 0 

REM 11 DR AW " , X0 h Y0 * L 1 , L 2 

1460 

M^I 

1030 

GDSUB 1000 


mo 


1470 

FOR T 0 =N 1 -i 1 TO N2 

1040 

M-l 


1 1 20 

x=xo 

l 480 

x*xo+Li*xm> 

10511 

IF N< 1 THEIN RETURN 


1 130 

Y- : Y0 

1490 

V”Y0+L2.*Y < TO ) 

1060 

X=X>L1*T1 


i mu 

GOSUB to 0 0 

150 0 

GO SUB 1000 

1B70 

Y-Y+Ll *12 


1 150 

M=1 

151 0 

NEXT TO 

18G0 

GOSUB 10 DO 


U6Q 

X-Ll 

1520 

RETURN 

1090 

IF Nm THEN RETURN 


1170 

Y=L2 

1530 

REM " POLYGON" ,XO,YO » L , A , N , N 1 

1700 

X~X -L2#TH 


11 HO 

GO SUB 1000 

1S40 

T U I / 1 0 0 

1910 

Y=Y-+L2*T1 


1 190 

RETURN 

1.&&Q 

Tl-2*ri/Wl 

1720 

CtlSUB 10 DO 


1200 

REM "LINE " . XO , Y 0 , L 1 , UE 

1560 

M”Q 

1 73(3 

IF NC3 THEN RETURN 


1210 

M=0 

1570 

x-xu 

1940 

X^XO L2*T2 


1220 

X=X0 

men 

Y=Y0 

1 750 

Y-Y0 I LEss-Tl 


1230 

Y-YO 

1570 

GOSUD 1000 

1 760 

GOSUB 1000 


1240 

GOSUB 1 00 O' 

1600 

M=1 

1 970 

IF N(4 THEN RETURN 


1250 

M=1 

1 6 J a 

rm T 2 =■ 1 TO W 

19B0 

x^xo 


1260 

X=X0 i l_l 

1620 

x-x+L^cosn'O) 

1V90 

Y“Y (3 


1270 

Y=YQ+L2 

1630 

Y & Y+L«SIN( TO 3 

2000 

COSUB 1000 


1 2 BO 

GOSUB 1000 

1640 

T0“T 0+T 1 

2qi a 

RETURN 


1290 

RETURN 

1 650 

GUSUB 1000 

2020 

REM ’'TIM ANCLE" . X0 , Y0 ,Ll ,L2 .A ,N 

1300 

REM " RADIUS \XD >YQ ,L,A 

1660 

NEXT T2 

2030 

TO- Ax-PI / 180 


1310 

TU-A*P1/1 80 

1670 

IF N<N1 THEN RETURN 

2040 

Ti=eum ro) 


1320 


1600 

X^XO 

aosa 

T2=SIN (TO > 


1 330 

X=X 0 

1690 

Y-Y0 

ao/.D 

M^(t 


1340 

Y-YO 

1700 

GO SUB in (HI 

2070 

X^XO 



103 


PRACTICAL COMPUTING October 1983 


VDUs and graphics 


plotting 


YO — starting Y co-ordinate 
L — length of radius 
A — angle of radius 


be drawn is also specified. The polygon 
may be drawn at any angie to the 
horizontal. Input parameters: 


Geometrical plotting 

Figure, line 1410. Draws an irregular 
figure. The co-ordinates of the vertices of 
the figure are passed as arrays in the 
parameters X and Y which must be set 
up before the routine is called. For 
example: 


100 N1 = 1 

110 INPUT N2 

120 DIM X(N2), Y(N2) 

130 FOR J = N1 to N2 
140 IN PUT X(l), Y(l) 

150 NEXT I 
160X0 = 0 
170 Y0 = Q 
180 LI s 1 
190 L2 - 1 

200 GOSUB 2100: REM “FIGURE” 

The parameters Ml and U2 specify the 
range of the arrays to be used; in this 
example the entire array is used. The 
parameters XQ, Y0, LI and L2 may be 
used to offset and scale the figure. Input 
parameters are: 


X0 — offset in the X direction 
Y0 — offset in the Y direction 
LI — scaling factor in the X direction 
L2 — scaling factor in the Y direction 
N1 — first array subscript to be used 
N2 — last array subscript to be used 
X — array containing X co-ordinates 
Y — array containing Y co-ordinates 


Polygon, line 1530. Draws a regular 
polygon. As well as the number of sides 
of the polygon, the number of sides to 


X0 — starting X co-ordinate 
Y0 — starting Y co-ordinate 
L — length of side 

A — angle of first side; normally zero 
N — number of sides to be drawn; 
normally equal to N for a complete 
polygon 

N1 — number of sides; must be three or 
more 

Square, line 1720. Draws a square. Drops 
through to the rectangle routine with the 
correct parameters to draw a square. 
Input parameters are: 

X0 — starting X co-ordinate 
Y0 — starting Y co-ordinate 
L — length of sides of square 
A — angle of first side; normally zero for 
horizontal square 

Rectangle, line 1760. Draws a rectangle. 
The size of the base and height, number 
of sides to be drawn and angle to the 
horizontal must be specified. Input 
parameters: 

X0 — starting X co-ordinate 
Y0 — starting Y co-ordinate 
LI — length of base of rectangle 
L2 — height of rectangle 
A — angle of first side; normally zero for 
horizontal rectangle 
N — number of sides to be drawn; 
normally four for complete rectangle 

Triangle, line 2020. Draws an isosceles 


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library of versatile Basie 
procedures which add a 
graphics-handling capability 
to your micro. 


triangle. The figure is drawn clockwise 
so that if only two sides are drawn then 
they are symmetrical. The angle from the 
horizontal may be varied. Input 
parameters are: 

X0 — starting X co-ordinate 
Y0 — starting Y co-ordinate 
LI — length of base of triangle 
L2 — height of triange 
A — angle of base 
N — number of sides to be drawn; 
normally three for complete triangle 

Circular curve plotting 

Arc, line 2240, Draws a circular arc. The 
centre of arc and the radius must be 
specified, together with the starting and 
finishing angles from the horizontal. The 
number of straight-line segments needed 
to make up the arc is calculated 
automatically and then the Segment Arc 
routine is used. The segment number 
calculation assumes a plotting area of a 
few hundred pixels in each direclton. If 
this is not the case on a particular 
system, then the division factor — 3 in 
this case — may need to be altered to 
obtain satisfactory results. For example: 

XQ — X co-ordinate of centre of arc 
Y0 — Y co-ordinate of centre of arc 
L — length of arc radius 
A1 — starting angle 
A2 — finishing angle 

Segment Arc, line 2260. Draws a 
segmented arc of a circle. The 
parameters are as for the Arc subroutine 

(continued on next page) 


ao m Y~Y0 
ztm GOSUB 1000 
2H1Q M-l 

2110 IF N< 1 THEN RETURN 

2120 X-XQ+LlttTl/2-L2*T2 

2130 Y*Y0+U*Tfc/ffi»is#Tl 

2145 GOSUB 1000 

21 SO IF Mis then return 

2160 X=X0 J-Ll*Tl 

2170 Y=T0+L1*T2 

2 ISO GOSUB 1000 

2190 IF N<3 THEN RETURN 

2200 X“X0 

2210 Y=YU 

2220 G0CUB 1000 

22 JO RETURN 

£240 Rlltt M ARC" , X0 ► Y0 *L , A1 > A2. 

2 25 [I W- 2 Q + im < L «A B*3 ( A 1 J / 1 [1 0 U > 

2260 RCn " SEGMENT AN C " » X D , Y 0 > L , A 1 , AS , N 

2270 TO^AIkPI/IUO 

22C0 Tl=A2*rl/lB0 

2290 T^m-TQVN 

2300 M=0 

2310 X-X0+L*COS<TU) 

2320 Y-YO+LwSlNCnn 
2330 GOSUB 1000 
2340 N=4 

2350 FOR 13=2 TO N 
2360 TO-T0+T2 
2370 X-X0*L*COS<T0) 

2360 Y=Y0+LttSlNCT0J 
2390 GOSUB 1000 
2400 NEXT T3 
24 IQ X~X[HL*C0C(Tn 
2.420 Y»YQ+L*SIN<T1.> 

2430 GOSUB 100(1 
2440 RETURN 


2450 REM "CIRCLE 'VXD > YO >L 
2460 N*20+lNT(L/37 

2470 REM “SEGMENT CIRCLE N , X0 , YQ , L ,N 

2400 TU=2*PI/N 

2490 M=fl 

2500 X-XtHL 

2510 Y=Y0 

2520 GOSUB 1000 

2530 M=1 

2540 T1 “0 

25*30 FON T2=2 TO N 

2560 T1=T1+T0 

2570 X=XOiL»COS<TU 

2330 Y=YQ+L#SIN(T1 J 

2590 GOLUB 1000 

2600 NEXT T2 

2610 X“X0« L 

2620 Y-YQ 

2630 GOSUB 1000 

2640 RETURN 

2650 HEM “POT" ,X0 f YU 

2660 X=Xfl 

2670 Y-Y0 

26S0 n - 0 

2690 GOSUB 10OO 

2700 M-l 

2/10 GtJ.CU B 100 0 

2720 RETURN 

2730 REM " POT GRIP* ,X0,Y0,L1 ,L2,N1 ,N2 
2740 TQ*Ll/.(til“l) 

2750 Tl=L2/fN2t> 

2760 Y=Y0 

2770 TOR T2=1 TO N2 - 
2700 X=X0 

2790 FOR T3-1 TO Nl 

2300 11=0 

2U10 GOSUB 10 011 


ueso m-i 

2030 GOSUB 100 0 
2340 X-X+T0 
2350 NEXT T3 
2B6U Y-Y+Tl 
2370 NEXT ra 
2330 RETURN 

2390 REM " DOT LINE" t X Q , YO > L , A , N 
2?M T0—A»P 1/180 
2910 T1=L*G0S<TU)/(N 1J 
2920 T2=L*tSIN(T0>/<N-l > 

2930 X=X0 
£740 Y-=Y0 

2950 FOR T3=l TO N 

2760 rt~0 

2970 GOSUB 1000 

2980 M-l 

2990 GOSUB l (30 0 

3000 X-X+Tl 

30 10 Y=Y +T2 
3020 NEXT T3 
3030 RETURN 

304(1 RIEM "UOTS" ,XO,YO ( L1 ,L2.N 
3050 FOR 10=1 10 N 
306 0 X^XO SLltfRNlHl) 

JU70 Y"Y0*L2*RM(i> 

3000 M=0 

3090 GOSUB 1000 

3100 

3110 GOSUB 1000 
3120 NEXT TO 
3130 RETURN 

314 0 REM ‘ARROU " , Xfl , Y0 ,L*L1 .A . A1 ,N 
3150 T0=A*PI/18O 
3160 Ti=Ai«r*i/iao 
3170 T2=X(ML*C0SU 0> 

31 CO T3=Y0-t L*S1N( 7Q ) 

(listing continued on next page) 


PRACTICAL COMPUTING October 1983 


109 


VDUs and graphics 


{continued from previous page ) 
except that the number of straight-line 
segments in the arc must also be given: 

XO — X co-ordinate of centre of arc 
YO — Y co-ordinate of centre of arc 
L — length of arc radius 
At — starting angle 
A2 — finishing angle 
N — number of segments in arc; must 
be 2 or more 

Circle, line 2450. Draws a circle, the 
parameters are as for the Arc routine 
except that the starting and finishing 
angles need not be specified. The 
number of straight-line segments is 
calculated automatically before the 
Segment Circle routine is used. As with 
the Arc routine, the segment-number 
calculation assumes a plotting area of a 
few hundred pixels in each direction. If 
this is not the case, then the division 
factor — 1,080 in the library routine 
shown — may need to be adjusted to 
obtain satisfactory results. Input 
parameters are: 

XO — X co-ordinte of centre of circle 
YO — Y co-ordinate of centre of circle 
L — length of circle radius 

Segment Circle, line 2470. Draws a 
segmented circle. The parameters are as 
for the Circle subroutine except that the 
number of straight-line segments to be 
used must also be given: 

XO — X co-ordinate of centre of circle 
YO — Y co-ordinate of centre of circle 
L — length of circle radius 
N — number of straight-line segments 

Dot-plotting routines 

Dot, line 2650. Draws a dot. A similar 
calling sequence is used by the rest of 
the routines in this section, input 
parameters: 

XO — X co-ordinate of dot 
Y0 — Y co-ordinte of dot 


Dot Grid, line 2730. Draws a rectangular 
grid of dots. The size and the number of 
dots in each direction must be specified. 
Input parameters are: 

X0 — X co-ordinate of bottom left-hand 
corner of grid 

Y0 — Y co-ordinate of bottom left-hand 
corner of grid 

LI — length of rectangle in X direction 
L2 ■— length of rectangle in Y direction 
Ml — number of dots in X direction; 

must be two or more 
M2 - number of dots in Y-direction; must 
be two or more 

Dot Line, line 2890. Draws a line of dots. 
The parameters are as for the Radius 
subroutine except that the number of 
dots to be plotted must also be 
specified: 

X — X co-ordinate of start of line 
Y — Y co-ordinate of start of line 
L — length of line 
A — angle of line 

N — number of dots in the line; must be 
two or more 

Dots, line 3040. Plots random dots in a 
rectangle. The number of dots must be 
given. The routine assumes that the 
function RND (1) returns a random 
number between 0 and 1. If not, it will 
need to be adjusted accordingly. Input 
parameters are: 

X0 — X co ordinate of bottom left-hand 
corner of rectange 

Y0 — Y co-ordinte of bottom right-hand 
corner of rectange 

Li — length of rectangle in X direction 
L2 — length of rectange in Y direction 
N — number of dots to be plotted 

General-purpose plotting 

Arrow, line 3140. Draws an arrow. The 
length and angle of the shaft and head 
must be specified. The head may be 
either open or closed. Input parameters 
are: 


X0 — starting X co-ordinate 

Y0 — starting Y co-ordinate 

L — length of shaft 

LI — length of head 

A — angle of shaft 

A1 — angle of head from shaft 

N — 0 for open head; 1 for closed head 

Dashes, line 3390. Draws a dashed line. 
The parameters are as for the Radius 
subroutine except that the number of 
dashes and the ratio of dash to space 
between the dashes must also be given: 

X0 — X co-ordinate of start of line 
Y0 — Y co-ordinate of start of line 
L — length of line 
A — angle of tine 
N — number of dashes 
N1 — ratio of dash to space between 
dashes 

Grid, line 3660. Draws a rectangular grid. 
Parameters are as for the Dot Grid 
routine, this time the grid is drawn with 
solid lines. 

X0 “ X co-ordinate of bottom left-hand 
corner of grid 

Y0 — Y co-ordinate of bottom left-hand 
corner of grid 

LI — length of grid in X direction 
L2 — length of grid in Y direction 
N1 — number of divisions in X direction 
N2 — number of divisions in Y direction 

Hatch, line 3890. Hatches In a rectangle. 
The number of lines used and the angle 
of the hatching are specified as 
parameters. For horizontal lines the 
angle is specified as zero; 90 degrees 
gives vertical lines. 

X0 — X co-ordinate of bottom left-hand 
corner of rectangle 

Y0 — Y co-ordinate of bottom left-hand 
corner of rectangle 

LI — length of rectangle in X direction 
L2 — length of rectangle in Y direction 
A — angle of hatching; between 0 and 
180 degrees 

N — number of hatching lines Q 


(listing continued from previous page) 

3550 

Y-Y+T7 



3560 

GQSUB 1000 

31 Y@ 

M=Q 

3570 

M-0 

320 0 

X=X0 

35 B0 

X=X *-T 4 

3210 

Y=Y0 

3570 

Y=Y+T5 

3220 

GQCUD 1000 

3600 

UDSUB 1000 

3230 

M=1 

361 0 

NEXT I 

3240 

X-T2 

3620 

X=--X0+L*T1 

3250 

Y=T3 

3630 

Y=Y04 LX-T2 

3260 

GOSUC 1000 

3640 

GO SUB 1000 

3270 

X=T2-L1 «C0S (Tl-TO) 

3650 

return 

32U0 

Y=T3+ LlJiSINtTl-m 

3660 

REM GR ID " , X 0 , Y 0 , Ll , L2 , Nl k N2 

3270 

GUGUB 1000 

3670 

TQ“L1/N1 

335)0 

IF N--D TULN H D !l 

3600 

x=xo 

331 5) 

X=T2-L1*CQS<T1+T0 ) 

3670 

FOR 11=0 TO NT 

3320 

Y=T3-L1*SIN(T1+T0) 

3700 

f1 n D 

3330 

UDSUB 1000 

371 0 

Y=Y0 

3340 

M=1 

3720 

GOUUB 1000 

3350 

X-T2 

3730 

H-l 

3360 

Y=T3 

3740 

Y=Y0 i LZ 

3370 

GO SUB 1000 

3750 

GDSUB 1000 

3360 

RETURN 

3760 

x=X+To 

3370 

REM "'DAStlCS " . XO ,Y0,L ,A.N,N1 

3770 

NEXT Tl 

34 0 0 

T0=A*P 1/180 

37 SO 

T0=L2/N2 

3410 

ti=coscto> 

3790 

FDR T1=0 TO N2 

3420 

T2=5tN(T0> 

30 OQ 

h- 0 

3430 

T3=L/(N*(N1+1 > 1) 

301 0 

X=X0 IL1 

344 0 

j 4=13*11 

3S&0 

GOSUD 1000 

34h0 

T5-T3'*T2 

3S30 

H-l 

3460 

T6=Nl*T4 

3G40 

X=X0 

34/0 

T7=N1 * TS 

3350 

GQSUB 1000 

3400 

0 

3B60 

Y-Y- TO 

3470 

x=xo 

3370 

NEXT Tl 

3500 

Y=Y0 

3LO0 

RETURN 

3510 

GDSUB 1000 

337 D 

REM "JfATCir^XQ , Y0 ,L1 >L2,A,N 

3520 

FOR 1=1 TO N 

3700 

T 0=14+1 

3530 

M= 1 

371 D 

T1=A 

3540 

X=X JT6 

3720 

IF < Tl < 0 ) UR (Tl > = 100) TULN T1=0 


3730 ir T1O70 T'tEM TE“A8St TAN< Tl 1/100 )> 
3740 T3=L1 /TO 

395 0 IF tTlOO) AND (Tl < >905 TULN T3“ 
tLULZm>/in 
3760 IF T1C70 TUEN T3- -T3 
3770 IF 11070 THEN 1 4=; (LI *T2-t La J/TU 
3700 TS=0 

3770 IF Tl < >70 TUCK T5=lNTtLE/T 4 > 

4000 T6°X0 

4010 IF Tl (70 TULN T6=XD+Ll 
4020 T7=X0 

4030 IF Tl >=70 TULN 17=XCHL1 
4040 T0--YO+L2 

4 0 "i o for xa=i tu n 

4060 T?=T0-T2 
4070 X-T6 

4 OUt) IF T2>T5 TULN X=T7-T?#T3 
4070 Y~T8 

4100 IF T2< e T5 TULN Y=Y.IK.TE*T4 

4110 N= 0 

4120 GOSUJl 1000 

4130 X=T7 

4140 IF T7>T5 TULN X=T6+T2*T3 
4130 Y- YO 

4 ICO IF T9<-=T5 TULN Y-T0--T7*T4 

4170 ft = 1 

41U0 GQSUP 1000 

4190 NEXT 12 

425)0 RETURN 

4210 REN 

4220 PI=4RATN(1J 
4230 RETURN 
424 0 REH '"RADIAN' 1 *A 
4 25U A=A*f*I/l80 
4260 RETURN 
4270 REH "DEGREE " „ A 
42t:i0 A*A*ie0/Pl 
4270 RETURN 


110 


PRACTICAL COMPUTING October 1983 




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Circle No. 168 



Colouring 

blocks 

Many shapes are difficult to fill using the BBC Micro’s triangle-drawing facility, 
John Dallman explores the possibilities offered by the new BBC ROM. 


ONE OF the few serious gaps in the 
graphics abilities of the BBC Micro was, 
until recently, the lack of a general- 
purpose facility for producing solid blocks 
of colour. While the built-in triangle- 
drawing facility is very useful, many 
shapes cannot easily be produced from 
triangles. 

It is sometimes useful to be able to fill in 
a shape which has been drawn, but whose 
boundaries are not known in a convenient 
form for the triangle-filling routines. 
Many kinds of graphs, shapes sketched by 
hand on the screen using a light-pen and 
landscapes for games are all difficult to fill 
using triangles. 

What was needed was an intelligent 
graphics routine that could be given a 
starting point inside any closed shape and 
then fill it with a specified colour. Some 
microcomputers already have software 
which will do this job. 

Now Acorn Computers has announced 
that some extra area- filling routines have 
been added to the BBC operating system. 
At first sight, they do not seem very 
impressive but a closer inspection shows 
that they are the basic operations for a 
very powerful algorithm which is well 
adapted to small systems. 

The new operating system calls fill a 
horizontal row of pixels with a specified 
colour. They are implemented as two new 
groups of Plot operations, and may 
therefore be used directly from Basic, An 
additional Os word enquiry call has also 
been added* and can be accessed from 
Basic through the Call statement. 

The techniques based on these new 
routines will only work on a BBC Micro 
with a Series 1 operating system ROM 
fitted. Owners of machines with the earlier 
version will find new ROMs available at 
BBC dealers and through the Beebug user 
group. The recursive techniques described 
by listing 3 will work on any BBC machine 
and* with modifications, on any system 
that allows recursive programming. 

The new Plot routines are available 
from Basic with the statement 
PLOT K,X,Y 

where K is the Plot option — 72 to 79 in 


this case — and X and Y are the co- 
ordinates of a point on the screen. When 
used, these routines start at the pixel 
specified by X and Y and search leftwards 
and rightwards along the same row for a 
pixel not in the current background 
colour. 

The search slops when it reaches the 
left-most and right-most pixels that can be 
reached from the starting point without 
crossing any pixel not set to the 
background colour. 

The system variables holding the last tw ? o 
positions of the graphics cursor are then 
set to the co-ordinates of these points, and 
a line is drawn between them. Table 1 
shows the exact meanings of X and K and 


Listing 1. 


to 

REM 

Program 1 - demonstration 

20 

REM 

of new BBC PLOT routines 

30 

REM 

in MOB 1.2. 

40 

REM 

By J.G.P.i liman, June 1983. 

50 



60 

MODE 

5 

70 



60 

REM 

Draw a tthape to be filled in: 

90 

REM 

a square 400 * 400* centered 

100 

REM 

at 600*500. 

110 



120 

MOVE 

400*300 

130 

DRAW 

800 , 300 

MB 

DRAW 

800 , 700 

150 

DRAW 

400 , 700 

160 

DRAW 

400,300 

170 



180 PROCpauset 10} 

190 



200 

REM 

Fill the square in in yellow. 

210 


22 0 

GC0L0*2 

230 

FOR V7. “ 300 TO .,700 STEP 4 

240 

PLOT 77 *600, Y7 

250 

NEXT 

260 



270 PRCJCpause (10J 

280 



290 

R£M 

Draw a line in. the back- 

300 

REPI 

ground dOl our f black > , 

310 



320 

GCDL0 , 0 

330 

MOVE 

6 00, 400 

340 

DRAW 

750,500 ' 

350 

DRAW 

600,600 

360 



370 

PRDCpauseUH ) 

380 



390 

REM 

Fill rightwards to that line, 

400 

REM 

iA red. 

410 



420 

DCDL0*t 

430 

FDR Y7 -t 400 TO 600 STEP 4 

440 

PLOT 93*500 *Y7. 

450 

T 

460 

END 


470 

DEF FROCpauselvecs} 

480 

REM 

Wait for 'mcs‘ Heconds. 

490 

LOCAL 

t 

500 

t - TIME 

310 Repeat 

520 

UNTIL TIME > t + 100»*ecs 

530 

ENDPRQC 


the types of line drawn for different Plot 
options. 

Plot options 88 to 95 work in a similar 
way but expect to be given a starting point 
not set to the background colour. These 
commands search for the last point that is 
not set to the background colour, moving 
away from the starting point. This point 
and the starting point arc used as the new 
values for the last two cursor positions and 
a line may be drawn between them. Table 
2 gives details of the individual com- 
mands. 

In listing 1 a square is drawn and then 
filled in using Plot 77 . A line is then drawn 
in the background colour* and an area to i 
the left of it is filled in with a different 
colour. The program uses mode 5 so that | 
individual pixels are dearly visible on the 
screen. 

The Step 4 statements in lines 230 and 
430 are important. The area-filling 
routines work in terms of physical pixels 
on the screen when searching, not 
1,280-by- 1,024 set of users co-ordinates. 
On the BBC Micro, there are only 256 
pixels on the vertical axis of the screen, so 
the Step 4 prevents duplication of and 
operation after a row has been filled. 

The routines work strictly in terms of 
logical colours and ignore any alterations 
of the default colours by VDU 19 
statements. If you happen to have two 
logical colours set to the same physical 
colour and are using one of them as the 
background colour the routines will be 
able to tell the difference even though 
none is visible on the screen . 

Selecting a new background colour with 
the GCol statement will not change the 
background until the screen is cleared. 
However* any of these new Plot 
statements used between selecting a new 
background colour and clearing the screen 
will treat the newly selected value as the 
background colour when deciding if a 
given pixel is set to the background colour 
or not. 

The new operating-system call has the 
form 

OSWORO 13 (&OD) 

It is used as an enquiry call, returning the 


112 


PRACTICAL COMPUTING October 1983 



VDUs and graphics 


STARTING POINT 




>©•••••• 

2# 


@1 

»< 

21 


la. Points 1-3 are on the stack. 


1b. Points 1,2, and 4 are on the stack. 1c* Points 1 and 2 are on the stack. 


tMMtmet 


• i •••••••©• 


•••••••••Of 

MIIHOHHI 

• t •••••••©• 

• • • mm 




• i •••••••©• 

• • ••©• 


Id. Points 1 and 5 are on the stack. 1e. Points 1 and 6 are on the stack. If. Points 1 and 7 are on the stack. 






mmmmmmmmmm&m 


• ••••• • 

• • •#©• 


•• • 


•#©••••••#©• 

• «• • mm 

m m •#©• 

• 


m mmmmm m 
mmmm 

9# •#©• 

• •#« 


1g, Point 1 is on the stack. 


!h. Point 8 is on the stack. 


11 Point 9 is on the stack. 


Figure 1. Area filling by runs showing a typically awkward shape. 


last two positions of the graphics cursor in 
user co-ordinates as four 16-bit binary 
values in an eight-byte control block that 
may be located anywhere in user RAM. 
Details of the layout of this block are given 
in table 3. The routine is entered at &FF1 
and is restored through &020C. 

Listing 2 contains a procedure called 
Proclocate, which may be used in other 
programs: a compressed version of it is 
used in listing 4. The procedure returns the 
co-ordinates as four integer variables, 
xl%, x2%, yl^o and ¥2%. The values of 
xl% and yl^o correspond to the X and V 
co-ordinates of the last position of the 
graphics cursor: x2% and y2% do the same 
for the last-but-one position. When used 
with either of the two new groups of Plot 
commands, xl%,yF% will be the co- 
ordinates of the right-most of the two 
points set, and x29k r y29fa will be the left- 
most point. 


The values returned by Osword 13 will 
always be rounded down to a multiple of 
the number of logical points, in user co- 
ordinates, in a pixel. They are stored 
within the operaiing- system RAM as 
addresses in terms of pixels, and are only 
converted back to user co-ordinates when 
requested by Osword 13. The conversion 
includes any resetting of the graphics 
origin that may have been performed by a 
VDU 29 call, and the returned values will 
always describe the pixel in which the 
orignally plotted point lay. 

Listing 2 simply draw's a line to a 
random position on the screen and prints 
the positions read back by Osword 13 on 
each time round the main loop. Of course, 
the last-x and iast-y values at any time will 
shift to being the last-but-one-x and last- 
but-one-y values on the next loop of the 
program. 

When you want to fill an area of the 


screen you are confronted with an area of 
pixels in a background colour, surrounded 
by a border of pixels in some other colour, 
possibly more than one. This border may 
be only one pixel wide, but may be more. 
It can be very irregular, with lumps 
forming a significant portion of the area 
to be filled. Figure 1 shows a typically 
awkward shape. 

A filling algorithm must examine the 
pixels surrounding the filled area and fill 
in those that are in the background colour. 
The simplest technique for doing this is 
shown in listing 3. It embodies a simple 
recursive algorithm which will fill any area 
provided that all the pixels belonging to it 
share at least one edge with another 
member. 

Such an area is known as a four- 
connected area* as opposed to the eight- 
connected type of area where two pixels 
(continued on next page) 


PRACTICAL COMPUTING October 1983 


113 


Colouring 

blocks 

(continued from previous page) 
are considered to be part of the same area 
if they simply touch at a corner. Figure 2 
shows examples of both kinds of area. The 
line-drawing algorithms used on the BBC 
Micro make four connected areas and 
would allow an algorithm intended to fill 
eight-connected areas to leak through any 
diagonal line. I will confine this article to 
four-connected areas , but you can find 
more about eight-connected areas in Foley 
and Van Dam’s quite excellent book 
Fundamentals of Interactive Computer 
Graphics , 

When you try out program 3 on any but 
the smallest target areas the recursive 


Table 1. Effect of Plot options 72 to 79. 

72 — X and Y are relative co-ordinates; 
no line is drawn, 

73 — X and Y are relative co-ordinates; 
a line is drawn between the two 
points in the current graphics 
foreground colour and action 

74 — X and Y are relative co-ordinates; 
a line is drawn in the logical inverse 
of the current foreground colour 

75 — X and Y are relative co-ordinates; 
a tine is drawn in the current graphics 
background colour 

76 — X and Y are absolute co-ordinates; 
no line Is drawn 

77 — X and Y are absolute co-ordinates; 
a line is drawn in the current 
foreground colour and action 

78 — X and Y are absolute co-ordinates; 
a line is drawn in the inverse of the 
current foreground colour. 

79 — X and Y are absolute co-ordinates; 
a line is drawn in the current 
background colour. 


Table 2, Effect of Plot options 88 to 95. 

88 — X and Y are relative co-ordinates; 
no line Is drawn 

89 — X and Y are relative co-ordinates; 
a line is drawn in the current 
foreground graphics colour and 
action 

90 — X and Y are relative co-ordinates; 
a line is drawn in the inverse of the 
current foreground colour 

91 — X and Y are relative co-ordinates; 
a line is drawn In the current 
background colour 

92 — X and Y are absolute co-ordinates; 
no line is drawn 

93 — X and Y are absolute co-ordinates; 
a line is drawn In the current 
foreground colour and action 

94 — X and Y are absolute co-ordinates; 
a line is drawn in the inverse of the 
current foreground colour 

95 — X and Y are absolute co-ordinates, 
a line is drawn in the current 
background colour 


Table 3, Control block for Osword 13 

00,01 — x co-ordinate of last-but-one 
position of the grahics cursor, x2% 
02,03 — y co-ordinate of last-but-one 
position of the graphics cursor, y2% 
04,05 — x co-ordinate of the last 
position of the graphics cursor, x1% 
06,08 — y co-ordinate of the last 
position of the graphics cursoe, y1% 
To locate 00 in the central block the 
routine is entered at &FF1 and is 
vectored through &G206. 


algorithm runs out of memory even with 
the minimal memory used by the mode 4 
graphics screen and the trivialy short main 
program. For small, complex areas this 
program can be useful, but it is not 
adequate for large areas with the amount 
of memory available in a non-professional 
system. The recursive procedure FROcec 
flood is called about 4*n + 2*m times 
where n is the total number of pixels 
within the area and m is the number of 
pixels within the border of the shape. Each 
call requires memory to hold the two 
parameters and the return address, so 
memory runs out pretty fast. 

What is needed is an algorithm that is 
rather logically complex but uses no 
recursion at all. The new routines are the 


fundamental operations for using this 
algorithm, and it is surprising that Acorn 
did not finish the job and add a full area- 
filling routine. Perhaps it will be included 
in the Graphics Extension ROM, when it 
appears. 

A workable version can still be 
implemented in Basic, and appears in 
Program 4. It runs in horizontal rows of 
pixels within the area to be filled, ending in 
a boundary of the area at each end. While 
it is not recursive, the procedure uses a 
stack on which the positions of the right- 
hand ends of all earlier unfilled runs are 
stored. The program uses separate stacks 
for the X and Y co-ordinates for the sake 
of simplicity. 

When a run is filled, the space above 
and below it is searched for unfilled runs, 
and stacks the co-ordinates of the right- 
hand ends of any unfilled runs it finds. 
The search uses both the new groups of 
Plot commands. The co-ordinates of the 
points to be stacked are found using the 
new Osword call, and the routine ends 
when the stack is empty. 

Figure 1 illustrates how the search 
works. Relative co-ordinate Plot calls are 
used with the variable dx% because 
neither group of calls can move the 
graphics cursor off the area of colour that 
it started in, but only up to a boundary. 


Listing 2. 

10 REM Program 2 

20 flErl Demonstrates use Of OB WORD 13 
30 REM by DRAWing to random locations 
40 REM on the screen, and then print- 
30 REM ing them out 
60 

70 KODE4 
■ 71 

72 REM Aloe ate parameter upar.v for 

73 REM OSWORD call. 

74 

75 DIM cords 7 

76 
G0 

90 REM Set text window 
95 

100 VDi) 23, 0, 4, 3V, 0 
1 IQ 

120 REPEAT 

121 

122 REM Mein loop of program 
130 

140 DRAW RNDtl279>,RND<864> 


145 

150 PROP locate 

155 

160 PRINT'" Last x "kI 7 . 

170 PRINT- Last y "yl* 

130 PRINT" Last-but-one w "x2I4 

190 PRINT- Last-but-one y >2* 

195 


200 PRlNT"PresS SPACE to conti nue”j 

201 

202 REPEAT 

203 UNTIL INKEY < -99) 

205 

210 UNTIL FALSE 
220 

5000 END 

10000 DEFPROClocate 
10006 

10010 REM Reads last position of the 
10020 REM graphics cursor into xLX,ylX 
10030 REM and the last-but-one position 
10040 REM into n27,y2X. 

10050 

10060 AK-13 

10070 n=cords MOD 256 
10080 Y7.=cords DIY 256 
1 0090 

10100 CALL&FFF1 
10110 

10120 K yb7 fc c or ds ! 0 
10130 Kyn^cords '4 
10140 ' 

10150 xLZ = h y n X MOP M0B00 
10160 ylK - M ynX DIV * 10000 
10170 *27. = xyn7 MOD 610000 
10180 y2Y. - «yo7. DIV 610000 
10190 

10200 ENDPRDC 


Listing 3. 

10 REM Program 3 

20 REM Da man strati CHH of simple 
30 REM recursive area filling. 

40 REM 

50 REM J.G. Dal loan, June 1983. 

60 REM 
70 M0DE4 
80 REM 

90 REM Draw a small , simple shape 
100 REM td fill. 

US 

120 MOVE 600,500 
130 DRAW 650,500 
140 DRAW 650,550 
150 DRAW 600,550 
160 DRAW 600,500 
170 

180 REM And fill it in.. 

190 

200 PROCr ec _f 1 ood i 625 , 525 ) 

210 

220 REM Walt for user 
230 

240 PRINT' "Press SPACE to conti be" 
250 

260 REPEAT 

270 UNTIL INKEVT-99I 
280 

290 REM Draw a larger shape 
300 

310 CLS 
320 

330 MOVE 3B0,30e 
340 DRAW 700,300 
350 DRAW 500,700 
360 DRAW 300,300 
370 

380 REM And fill it in - or try... 

390 

400 PROCr ec _f 1 Ood 1 580 , 500 > 

410 

420 END 

430 DEF PROCrec_flocid<*,y> 

440 

458 REM Kave we reached the edge of 

468 REM the shape 7 

470 

480 IF POINT (x,y> > 0 THEN GOTO 600 
490 

500 REM He haven't, so fill it in 
518 

520 PLOT 69 ,K ,v 
330 

540 REM And try the points ar round It 
330 

560 PROCrec_f 1 ood £x^4 , y ) 

570 FROCrec_f 1 crad tx +4, y J 
580 PROCrHC_flM>dCx,y-4) 

390 PROCr ec„f 1 ood tx , y+4) 

600 ENDFROC 


114 


PRACTICAL COMPUTING October 1983 




VDUs and graphics! 


The variable dx% is set to the horizontal 
size of a pixel in the current screen mode 
by FNhorstep so that the move over the 
boundary can be performed reliably. 

Very little stack space is used by this 
technique, except for areas that branch 
out into many small ones. A machine-code 
version should therefore be quite 
practical, even given the restricted stack 
space available on the Micro’s 6502 
microprocessor. The new Plot routines are 
not very fast, and an instantaneous fill 
seems impossible. Taking Rem lines out of 
the Basic version and using multl- 
statement lines can speed it up about 30 
percent, although that is still rather slow 
for use within applications programs. 

It is possible to extend the filling 
technique to fill areas of foreground 
colour, and to change the colour of ready- 
filled areas. More details can be found in 
A R Smith's article, Tint Fill, in 
Computer Graphics, August 1979. 
Acorn’s routines in their current form may 
not allow, all the possible extensions. In 
that case disassembly of the relevant 
sections of the operating-system ROM 
should give a good idea of how to write 
additional routines along the same lines. 

Figure 2, Four and eight -connected 

area. 



2a. Four-connected areas. 



2b. Eight-connected areas. 


Listing 4. 

LB REM Program 4 “ 

20 REM Demonstration of nob-recurs- 
30 REM ive iroa filling. 

40 REM 

SO REM J.G. Dali man, June 19S3- 
60 REM 
70 

80 MODE 4 
90 

100 REM Dimension parameter block for 
US REM PROClQGate. 

120 

130 DIM cords 7 
140 

150 REM Dimension arrays f DT software 
160 REM stacks. 

170 

160 DIM 128) ,syXU20) 

190 

200 SPWAJt - 0 

210 

220 

230 REM Draw a large, complex shape 
240 REM to fill. 

250 

2*0 MOVE 200,200 
270 DRAW 250,450 
200 DRAW 500,180 
290 DRAM 1000,270 
300 DRAW 1100,0 
310 DRAW 1200,600 
328 DRAW 1100,250 
330 DRAW 500,500 
340 DRAW 400,400 
350 DRAW 200,500 
360 DRAW 200,280 
370 
360 

390 REM Fill in the shape 
400 

410 PRDCfloodi 450,300,1) 

420 

430 

440 REM Print men turn value of software 
450 REM stack pointer. 

460 

470 PRINT " ‘ SPHAX - "l El MAX 
480 

498 END 

580 

510 

520 DEF PRtJCf load OC,Y, tint! 

530 

540 REM Initialise variables. 

550 

560 stackptrX = 0idxX « FNhorstep 
570 stacktopxX * -listaektopyX - 
580 

598 REM Set colour for filling. 

600 

610 ECOL 0 , t i nt 
628 

630 REM Push starting co-ord i nates 
64® REM for first time round loop. 

650 

660 PR0CpusM)E,Y) 

670 

600 

690 REM Main loop of procedure 

700 

718 REPEAT 
720 

738 REM Pop starting coordinates 

740 REM off software stacks. 

750 

760 PRDCpop 
770 

780 REM Pill across this y “co-ordinate. 
790 

808 PLOT 77 , stacktopxX, st ACktopyX 

@10 

820 REM Locate points and set Up the 
030 REM *#baseV. variables. 

840 

B50 PROC locate 

860 

870 * 1 b a soV.= K 27.1 y 1 b A*«X«V 27. 

800 xrbaseX^MlXiyrhaseji^yir. 

890 

900 

918 REM screen 6 try to fill the line 

920 REM above the current one- 

930 

940 IF POINT Cxi baseX, yl baseX-4 > < >-l THEN 
PROCsearch(-4J 

950 IF PPiNT (xlbaseX,ylbase7-r4) 0-1 THEN 
PRQCseareMA) 

960 

970 UNTIL staekptrX^O 
980 

99® REM We've run out of lines to fill 
1000 

1010 ENDPRDC 
1828 
183® 

1040 

1050 DEF PRGC&earch (dyX) 

1060 

1070 REM Searches for unfilled runs on 
4080 REM the line above or below the 
1090 REM current one- 
1100 

1118 LOCAL wX,yX 
1 120 

1 130 REM He have started abov»7below a 
1140 REM point that can be lit or .not - 


1150 REM this handles that case. 

1168 

1178 IF POINT Lx IbaasX ,yl baseX+dyX> *=0 THEN 
PLCT76,xlbaseX,ylbaeeX+dyX ELSE PL8T9 
2 , M 1 ba seX , y 1 b ameX+d yXt" PL0T72 T d x X , 0 
1180 

1190 REM Locate th* point *the right 
1200 REM end of a run) found aboye. 

1210 

1220 PROC locate 
1230 f 1 aqX=FALBE 
1240 REPEAT 
1250 

1268 REM Search rightward for right ends 
1270 REM of runs and push them onto the 
128® REM software stacks. 

1290 

1300 IF X 1 X > xrbaseX THEN flagX=TRUEi 
GOTO 1340 

1310 PROCpushlKlX,ylX> 

1 328 FL0T92 , x 1 X+dxX , y 1 % 

1330 PLOT72, d+r7. , 0 

1340 PROClocate 
1350 UNTIL flagX 
1360 

1370 REM The search has gone beyond the 
1380 REM right end of the previous run. 

1390 

1400 REM Check if the run we're working 
1410 REM on extends beyond the base run 
1420 REM to the right - if so find it's 
1430 REM right end and push that. 

1440 IF P01NT(Krba^eX,yrbas«X+d¥XJ =8 THEN 
PLGT76 , xrbftSeX , yrbaseX+dyXi PRQC1 ocate 
sPRQCpuaht* IX, y IX) 

1450 

1468 EWDPRDC 
1470 

1480 DEF PRQCpush ( XX ,yX > 

1490 

1500 REH Puts xX and yX onto the soft- 
1510 REM ware stacks and into stacktopxX 
1520 REM and stacktopyX. 

1538 

1540 REM Check w* haven't stacked these 
1558 REM points already, 

1568 

1578 IF xX^stacktopxX AND yX“st*cktopyX 
THEN GOTO 166® 

1380 

1598 REM Perform stacking 
1600 

1610 HxXtBtaekptrX>-xXi*yX(st*ckptrX>-yX 
1620 stacktopx X*>x X 
1630 stacktopyX-yX 

1640 etackptrX=staokptrX+l 

1641 

1642 REM Check value of software Stack 

1643 REM pointer. 

1650 IF stackptrX >SPH AX THEN SPHAJ(= stackptrX 

1660 ENDPROC 

1670 

1680 DEF PRDCpop 
1601 

1682 REM Pop software stacks and set 

1683 REM new values of stack t op xX and 

1684 REM staqktopyX. 

1690 stackptrX»atackptrX-l 
1 708 stack top kX^sx X IstackptrX) 

1710 stacktppyX^ayX <st aokptrX ) 

1720 ENDPRQC 
1730 

1740 DEFPROC locate 

1750 AXwi3<XX*cordv MQD 256 

1760 YX*corde DIV 256 
t 770 CALL&FFFl 
1780 xyo=cords!0 
1 790 x yn*=cordis ! 4 

1880 xlX-xyn HOD6 100001 y 1X=* yn DI9&18008 
1810 x2X"Xyo MODV 180801 y2X=wyo D 1 96 10000 

1820 ENDPROC 

1821 

1B30 DEFFNhorstep 

1831 

1832 REM Returns horizontal size of 

1833 REM pixel in current mode. 

1834 

1840 AX* 135 

1841 mndeX=*USRttfFFF4> 

1042 rrlodwX=madeX. AND tFFFFFF 

1843 mod eX-mad »X DIV&1808® 

1844 IF mOdeX=3 OR modeX>5 THEN PR I NT ‘Wrong 
mq de , dunwi y > [ ■ ■■ * STOP 

185® IF modeX=0 THEN =2 ELSE IF tjDodeX*! Oft 
JtlodeX=4> THEM *4 ELSE sQ m 


References 

Beebug Newsletter, Acorn News, 

Volume 1, Number 6, October 1982. 

Fundamentals of Interactive Computer 
Graphics by Foley and Van Dam, 
Systems Programming series, 1982. 
Published by Addison-Wesley. 

Tint Fill by A R Smith in Computer 
Graphics, August 1979. 


PRACTICAL COMPUTING October 1983 


115 


Images 
of digits 

Peter Kruger and Stephen Cronk of Digithurst Ltd 
explore the potential for high-resolution vision systems. 


for some time the subject of image 
analysis has interested engineers and 
computer scientists. The ability to put a 
graphical representation of a real object 
into a computer and manipulate it has 
found countless applications from pattern 
recognition to CAD. Until recently most of 
the available vision hardware was based 
around either mainframes or specially 
designed processors; it did not have the 
general applications which would allow 
high-volume sales over which to spread 
development costs. 

The microcomputer has a wide range of 
applications from office administration to 
process control and is proportionally lower 
in cost. Rather than using external 
hardware such as CPUs and RAM to 
capture the image the micro's own 
hardware is used as a frame store. The data 
becomes much more accessible to the user 
for the purpose of image processing. 

Solid-state cameras provide the 
computer with digital data representing a 
map of pixels, which make up the image 
failing on the sensors of the camera's solid- 
state array. 

Due to the low level of production solid- 
state cameras can be quite expensive. This 
is changing and solid-state sensors are being 
applied to a range of consumer products. 
Some solid-state cameras use optic RAM 
rather than a sensor. This enables an image 
to be fed straight into RAM, and the sensor 
itself to be read in the same way as a frame 
store. It provides a very rapid, low-cost 
method of obtaining a binary image. 

The alternative to the solid-state camera 
is the Vidicon television camera which 
provides an analogue signal, which is then 
digitised. Unless expensive A to D 


converters are used this method is slower 
than the solid-state camera, but it does have 
the advantages of being both low cost and 
giving a grey-scale output. In general terms, 
where the object being analysed is slow 
moving and a grey- scale image is required a 
television camera system can be used. If a 
rapid access time is required and a binary 
image is sufficient, then a solid-state system 
should be used. 

To carry out analysis the image data can 
either be sorted in external RAM, in the 
camera or frame store, or in the 
microcomputer itself. Advantages and 
disadvantages are present in both systems. 
The cost of external memory and the extra 
processing required is high, but may be 
necessary if the image analysis required is 
complex and takes up a large amount of 


RAM. If the microcomputer is large 
enough to hold the image and the software 
required, then the data becomes much 
more accessible to the user and the cost of 
additional hardware falls. 

Once the image has been captured and 
stored it may be desirable to display it. The 
image may be shown as a binary or a grey 
scale. If a binary display is required the 
data must be scanned and each pixel 
compared to a preset threshold before 
deciding to display them or not. To 
simulate grey scale a group of screen pixels 
are used to represent each camera pixel. 
The thresholding technique is used for each 
pixel within the group and an image is 
displayed not dissimilar to newsprint. A 
contrast value can be used to set the 
threshold values for the pseudo grey scale 


Figure 1. 


128 pixel elements 


The data structures hold data in unprocessed or 
processed forms. Figure 1 shows unprocessed data, 
which is held in RAM. Figure 2 shows processed data 
which is unprocessed data that has been encoded. 


Figure 2. 

r? 


Laign EHHB-tg 

\ v 


□ 


l 1 

i__J I 


FifSl 
position 
of run 


CoFour of run - 1 for white 
0 for black 


Number of pixels in run 



A grey-scale image. 



A binary image. 




i 


116 


PRACTICAL COMPUTING October 1983 






VDUs and graphics' 


display. Both routines can be written using 
the computer’s point-plot routine making 
the software transportable between 
different micros. 

Data may take one of two forms when it 
is read into the computer. It may either be 
binary image data and be bit mapped or it 
may be grey-scale data and be byte 
mapped, each byte having a value 
representing the brightness of the respective 
camera pixel. At this point it will be 
necessary to clean up the image. High- 
resolution pictures gained with a video 
camera which has random interlace must 
have the effect of the interlace removed, 
which is achieved using recursive pro- 
cessing. 

This is a relatively simple yet effective 
way of reducing noise or any form of 
sporadic interference on a digitised 
television picture. A number of frames are 
captured, each being averaged with the 
previous using the algorithm: 

NEW PIXEL = (OLD PIXEL INCOMING 

PIXEL)/2 

The random nature of the interference 
means that over a number of frames the 
unwanted noise will tend to cancel out. 
Increasing the number of frames captured 
and averaged in this way improves the final 


result but also increases the time taken to 
reach that result. It is usually found that 
acceptable results are achieved after the 
first three or four frames; after that the 
small improvement in picture quality is 
minimal compared to the extra time 
needed. 

A slightly more advanced version of the 
technique which leads to more flexible 
filtering allows the user to define the 
proportion of the incoming image that is 
mixed with the previous image, using the 
algorithm: 

NEW PIXEL=K*OLD PIXEL + 

(1 — K)*INCOMING PIXEL 
where K is a user-specified constant 
weighting the new image. 

Recursive processing techniques can also 
be used to intensify a low-level video signal 
such as one that is shot out of doors at 
night. Each captured frame is summed with 
the previous frame so that over a period of 
about 10 frames, depending on the light 
level, a clear image can be seen. The process 
requires the image to be stored in 16-bit 
words as it is quite likely that the values 
obtained may be greater than 255. 

To remove any electrical noise appearing 
as individual pixels, or marks and small 
objects which appear as single pixels and 



therefore cannot be verified at the current 
resolution, the image data is cleaned. The 
cleaning consists of examining pixels in 
groups of three and eliminating any pixels 
whose neighbours differ radically in 
intensity. 

Image compaction techniques can be 
used to reduce the size of the image-data 
file to speed up data access during future 
processing. One method of data 
compaction is run-length encoding which 
reduces the memory required to hold an 
image by up to 16 times. Each pixel is 
examined and compared with the current 
threshold value. The next pixel in the 
current raster is also compared to the 
threshold value, and a run of pixels of the 
same thresholded value is built up. Each 
run is stored in a three-byte record, the first 
byte giving the start point of the run, the 
second byte the number of pixels in the run, 
and the third the colour of the run. 

The amount of grey-scale and processed 
data which can be held at any one time will 
depend on the memory size of the computer 
being used. For example, a 256K Sirius will 
hold a 256 by 256 grey-scale image 
occupying 64K as well as at least one 
processed image at any one time. This 
allows the image to be processed at various 
thresholds without disturbing the original 
data. 

Object/pattern recognition can be 
undertaken either by using values of area 
and perimeter or by examining the grey- 
scale data in greater depth. By using edge- 
detection methods it is possible to build up 
a series of co-ordinates which can be passed 
to a CAD software package. 

With the introduction of more powerful 
microcomputers and with greater speed and 
memory mapping capabilities there is a 
greater potential for higher-resolution 
vision systems. To anyone who has spent 
hours inputting graphics into their 
programs the applications of low-cost 
vision systems is obvious. Images can be 
used as backgrounds for games programs 
or computer-aided learning software with 
images being read in and reduced to line 
drawings in a matter of seconds. [J 



Grey-scale image with edge detection on one section. 



Inverted image with edge detection on one section. 


PRACTICAL COMPUTING October 1983 


117 



Death to 
the machine 


M andy’ s eyelashes flickered open, 
slashing the teardrop that welled in 
the corner of her eye. Memories of the 
night’s storms overwhelmed her. She drew 
back, hating the world that had invaded 
her sleep and ruthlessly dragged her back 
to reality. 

A dog barked in the avenue below. A 
blackbird’s vivacious song rang out. 
Dazzling sunshine illuminated the curtains 
and showered the room in gold dust. 

Henry sensed her waking, and he 
remembered the way she had quaked when 
the rolls of thunder and lightning had 
terrorised the night. Gently he touched her 
skin. To reassure her, he told himself. 

They lay together side by side, aware of 
each other but not speaking, choosing 
instead the intimate silence of lovers. 
From the corner of her eye she watched 
him, his body bronzed in the mist of 
sunlight. She was afraid to move, to 
speak, afraid of destroying the- moment. 

At last he rose, silhouetted against the 
curtains, innocent of his own nakedness 
and his partner’s idolatrous gaze. She 
studied him jealously — his flawless skin, 
his broad shoulders and pronounced 
muscles, his grace. He moved like a 
panther. 

“Good morning Amanda,” he said 
with a sparkling smile. 

“Morning Henry,” she whispered. 

He carried her across the room and 
deposited her in the wheelchair that stood 
dormant in the corner. He felt no 
revulsion at the ugliness of her wasted 
limbs. Sympathy never crossed his mind, 
Mandy watched him carefully. She 
hesitated nervously, then at last plucked 
up courage to speak. 

i4 Last night ... Henry. Thank 
you .... I know it broke all the rules. 
But i needed you,” 

Henry nodded a silent acknowl- 
edgement, 

“Lights. Curtains.” He gave the 
command as he left the room. The lights 
dimmed themselves and the curtains drew 
back, engulfing the room in light. 

M andy tucked into her breakfast 
with relish, scooping up the pieces of 
bacon with the fork in her right hand. The 
left was draped uselessly in her lap. 
“Television I,” she ordered, and the 


television obligingly flickered into life. 
The Breakfast G’ Clock News held her 
attention as she ate. 

An explosion. The crashing and 
splintering of glass and wood. People 
running, shouting, throwing, hating. The 
crack of gunfire. Police armed to the 
teeth, charging. Panic. People screaming. 

Mandy was sickened, but the screen 
compelled her to watch, holding her eyes 
the way a swaying cobra hypnotises its 
prey. 

“A spokesman for the company, Robo- 
of-A mer iea, said that 10 robots were 


by Andrew Walker 


completely destroyed and several others 
had been severely damaged, putting the 
cost at 13 million dollars, 37 rioters were 
reported killed/’ 

The robot newsreader spoke in cold 
tones, reading the idiot -tape that ran 
through his wrist, “The President 
attacked the left-wing militants who, it 
was said, were using people in a political 
game. By telling people that big business 
was replacing humans with robots, the 
communists were feeding on the fears oT 
the working class for their own subversive 
ends. She added that we must all make 
sacrifices.” 

On the screen a robot was being 
dismembered by the rioters, while another 
was catapulted from a third floor window, 
Henry shuddered. 

But Mandy was bored, numbed to the 
violence by its day-by-day repetition, 

“O hopping,” Mandy commanded, 

LJThe television picture blinked out 
and a menu appeared, cursor flashing. 
Her fingers played deftly on the console 
installed on the right arm of her chair. She 
looked for things they were running out of 
— food, polish, toilet rolls. She compared 
prices and ordered items. She picked the 
colours that took her fancy and went 
window shopping for the latest fashions. 
New screens continually sprang into view, 
choices were made at leisure. 

“What do you want to do today?” 

Henry fired the question into the air as 
he worked, not looking at Mandy, 


“Take me home, please. You know 1 
want to go,” 

“This is your home.” 

“My real home,” she pleaded. 

Henry paused, 

“You know what I think about going 
there. 1 don’t like it. It’s dangerous — full 
of thugs and hookers, 

“And it’s not your home — not any 
more. It’s not the quiet suburb of your 
childhood. Wipe those memories away for 
your own sake,” 

i£ Take me," Mandy persisted. 
“Please.” 

Henry bit his lip, but replied reluctantly: 
“All right. You know l can never say no to 
you,” 

T he Hill was home. Tree-lined 
boulevards, pipe-smoking artists 
lazing on street corners, discussing Picasso 
and extolling the beauty of the girls as they 
walked by. Sunny days, and families 
taking the air in their Sunday best, 
nodding to passing acquaintances. 

It was all tong gone. Buildings rotted 
and neglected streets flowed with garbage. 
The Hill groaned under man’s physical 
graffito. 

Henry sensed the eyes on them, 
strangers in a strange land, anachronisms, 
belonging even to a different species. 
Faces hid behind curtains that flapped in 
open windows, through which the 
shadows of the rooms within seemed to 
give each building an aura of dirt and 
doom. 

Mandy saw her childhood. The family 
and the home. The breaking of morning 
across the rose-tinted garden. Her friends. 
The birds that spoke to her. The way she 
would run through the dew-laden grass, 
chasing or being chased, laughing and 
shrieking with joy. 

“Satisfied?” Henry asked malevolently. 
“See how ugly this place is. We shouldn’t 
have come.” 

But Mandy was far away. 

mash the bastard!” 

The mob fought hard for the right 
to kick and punch its victim. People ran, 
jostled, writhed like maggots, a seething 
mass of frustrated, angry bodies. They 
vented their hatred, emptied their sack of 
fears, and found relief in aggression. 


118 


PRACTICAL COMPUTING October 1983 


■Fiction 



Moving down the street, heedless of 
passers-by, the amoeba broke and 
reformed, then broke again, and finally 
raced ahead, exhilarated by pain and 
violence. Each man was caught by the 
mood of blind rage, joining in the bailing 
and killing of guilty and innocent. 

They tired, but as they dropped their 
places were taken by others, ever more 
eager, ever fresh and hungry, charged by 
the electricity of the moment. They 
grabbed a drone as he hauled a crate 10 
times his size, descending on him like 
vampires. He struggled briefly before 
drowning in a sea of people. Cheering 
people, revelling in destruction, throwing 
parts of the drone hither and thither, 
people turned mad on a balmy Sunday 
afternoon. 

“This one won't steal a man’s job 
again. Get out of the way — let me kick it. 
Death to the machine!’* 

Henry shivered as he looked at the 
grieving, stricken torso. A stranger 
staggered along the street from the 
direction of the mob. His head head hung 
low, but as he neared Henry he looked up 
with glazed eyes. He was pale as death, 

“They ... they ripped him apart. ” He 
trembled with each word. “A man. They 
did it to a man.” 

Henry turned, leaving the stranger 
retching in the gutter. He pushed Mandy 
along, glowering at the back of her head. 

“Damn you!” he thought, “I told 
you,” 

And his circuits wondered at this new 
emotion. 

here’s another!” voices cried. 
Fingers darted in a million 


directions. The voices grew in number. 
Factions split, intoxicated by violence, 
dashing over their prey like packs of 
hyenas. 

“There's one!” 

The cry pealed out like church bells, 
across the streets and through the alleys, 
to shoppers, to people leaning from 
windows with ghoulish curiosity, to a 
mongrel that paused briefly as it chewed a 
robotic leg, to a gang prising open a Space 
Invaders machine. To a new victim. It 
tolled the death knell, 

A strong, steady finger pointed. The 
finger of the hard man. A compelling 
finger that urged the eye lo follow its line 
to the guilty man who stood there 
dumbfounded, still holding on to the 
wheelchair in which his prisoner sat, a 
poor, weak-looking human girl. 

The cry tolled out for Henry. 

He broke into a run. With a wave of his 
arm the hard man commanded the crowd 
of onlookers to give chase. But they were 
on their way already, stirred by 
propaganda, feverishly wanting to free the 
girl from the inhuman monster. 

The wheelchair careered madly as 
Henry galloped, hounded by the baying 
hunters. He swung round corner after 
corner, in and out of alleyways, trying 
vainly to shake them off. The mob 
struggled, a cursing, stumbling rabble. 
But always he sensed the hard man hard 
on his heels. 

eave me Henry. Run.” 

Mandy's pleas grew as the 
wheelchair rocked and rolled and Henry’s 
silence lengthened. 

His circuits burst with energy, 


transceiving messages. Logic chips warned 
him of the danger to Mandy, how she 
would be mistaken for a robot, how she 
would be mutilated, how the humans 
would kill her from instinct alone. Chips 
of intuition calculated probabilities — 
the chance of her neck being broken if they 
kept the present speed, her chances of 
survival if he left her. 

“We are 74 percent certain that a savage 
band of humans would not harm a cripple 
girl,” they said. “Save yourself,” cried 
out self-preservation units. 

But wise old legal chips read the rules: 
“ You cannot leave her to a doubtful fate; 
preservation of the machine is secondary. 
Self-sacrifice is an honourable death.” 

“Leave me,” Mandy added. 

“Can’t,” Henry stammered, finally, 
through gritted teeth. 

“Run Henry, run,” Mandy pleaded 
tearfully. 

“Run rabbit, run,” bellowed the hard 
man, like a blast from the farmer’s gun. 

The packs closed in, howling 
triumphantly as their prey froze, each 
eager to cheat the other of its kill. And 
then the hard man stood face to face with 
Henry. 

H enry’s brain tore into itself. 

Logic clashed with law. Morality 
proclaimed. Self-preservation cried it 
down. “Kill him — you can't kill a human 
— it's your only chance — his life or hers 
and yours — Primary Robotic Law 
states ...” 

Anonymous circuits assented or 
dissented in a clamour of a billion 
electronic pulses. He clutched his head. He 
(continued on next page} 




PRACTICAL COMPUTING October 1983 


119 


Fiction 


Death 
to the 
machine 

(continued from previous page) 

argued and proposed solutions and then 
dashed them all against the wall of robotic 
law. 

The hard man smiled knowingly. With a 
crayon he began to daub Henry’s forehead 
in blue: “666”. The number of the robot, 
reckoned the propagandists. 

Henry seethed with rage. He let go a 
bellow, like a trapped animal caught 
without hope, a bellow that turned to a 
scream of anger and shame. A scream that 
became a flash of insanity. 

A clenched fist lashed out, breaking the 
invisible barrier: for an instant Henry 
became human. The hard man’s jaw 
cracked behind the punch, and like a man 
possessed, his whole body convulsed in a 
wild frenzy. 

Henry stepped back aghast, shocked by 
his violence, disowning the fist that had 
offended, and repulsed by the spectacle 
and nauseating fumes before him. A flood 
of integrated circuits, cogs and lengths of 


wire poured from the hard man’s mouth. 
His head erupted, shattering into a billion 
slivers of silicon. 

Suddenly all was quiet, his death throes 
exhausted, his headless corpse frozen 
upright, erect for eternity. The stupor that 
hung over the scene held everyone as Henry 
edged away. No one followed. 

“TT e was just a tool,” Henry 

JL X insisted. “Like the video games, 
like the bus driver. Like me.” 

“I don’t understand.” Mandy repeated 
the statement for the umpteenth time, 
chafing Henry’s nerves like sandpaper on 
an open wound. 

Birds were singing in the trees. The sun 
shone from a clear sky. Towering over her 
stood the city, a warm paternal giant 
whose strength comforted her, a city of 
glass skyscrapers, hygiene and 
automation, where there was light and no 
shadows, where the people thought of 
peace and beauty. 

Henry knelt in front of her as she wiped 
the blue scrawl from his forehead, fussing 
maternally. She avoided his eyes. “He was 
a robot — all your militants use them,” 
Henry explained. They’re programmed to 
seek out other robots, stir up feeling 
against them, incite riots: a Judas. Built to 
slaughter his own.” 

“It’s always the same,” he went on. 
“Cars, television. You invent these things, 
make the world a better place. Then what? 
You’re lost. You take them for granted, 


ignore them, distort them, manipulate 
them, turn them to evil and then learn to 
fear and hate them. 

“You wonder at your own power: 
you’ve made something in your own image 
— you are God. But you’re afraid — it’s 
better than you. So you tear it down. Seek 
it out, cut it out like a cancer.” 

Mandy was pinned to her chair by the 
venom in Henry’s tongue and the crazed 
ravings of his mind. She trembled in fear 
of the stranger before her. 

Circuits raged in new-found freedom, 
or cowered in seclusion, screaming their 
terror of this brave new world. 

losedown.” 

The command froze Henry in 
mid-sentence. His eyes closed. He was 
suspended in time. 

“Re-initialise,” God commanded. 

Henry flickered into life, and a warm, 
comforting smile spread on his lips. 

“Isn’t it a lovely day, my love?” He 
spoke in a sickly sweet voice that chilled 
her spine. “Let’s go to the park.” 

The crisis was over, but a malevolence 
crept into his face, a malevolence that even 
God did not detect. It distorted his 
features and set a darkness in his eyes as it 
spread to his powerful arms. 

Below them the avenue stretched down 
to the wharf, where streetside cafes 
vibrated with life, and the sun smiled on 
the rich, beautiful people. Henry began to 
loosen his grip. Q 



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PRACTICAL COMPUTING October 1983 


121 





A question of 
significance 

With Owen Bishop’s Basic programs you can tell chance from choice. 


“coffee, tea or me?” Ignoring the “Me” 
of the memoirs of those incorrigible airline 
stewardesses, Trudy Baker and Rachel 
Jones, still leaves you with a choice to 
make: shall it be tea or shall ii be coffee? 
It must be one or the other, but you are not 
allowed to have both. To put it more 
technically, they are mutually exclusive 
choices. 

This kind of choice is thrust upon you 
many times a day. Sometimes you make a 
response based on a strongly felt 
preference or a reasoned argument. But 
often you are indifferent and decide on a 
whim or by tossing a coin. Your choice 
might just as well be the result of running: 
10 choice = RND(2) 


20 IF choice = 1 THEN PRINT “Coffee’ 1 

ELSE PRINT “Tea". 

Suppose a board of directors is offered 
tea or coffee and all choose tea. Does it 
mean that they genuinely prefer tea? Is it 
worthwhile brewing up coffee next time? 
A majority of six to none seem a strong 
one, but can you be sure that the board has 
a genuine preference for tea? 

There is no need to go into the reason 
for the preference, if there is one: the tea 
may be superb, the coffee may be like 
dishwater or maybe they are just a bunch 
of cha-wallahs. You just want to know 
whether they have a genuine preference or 
made their choice through whim. 

Suppose the directors had no strong 


reasons for their choices and each decided 
to run the random-choice program on the 
firm's mainframe and imbibe accordingly. 
Any given director is equally likely to 
select tea or coffee, unless there is a bug in 
the mainframe or its random-number 
algorithm. Six different outcomes are 
possible: 

all six choose tea 

five choose tea and one chooses coffee 
four choose tea and two choose coffee 
three choose tea and three choose coffee 
two choose tea and four choose coffee 
one chooses tea and five choose coffee 
all six choose coffee 

These seven eventualities are not equally 
likely to occur. For instance, there is only 


20 



20-i 


18- 


16- 

CO 


c 

o 

14- 

■+— * 

H— 1 

L_ 

12- 

CO 


a 

h— 

10- 

o 


0 

8- 

n 


E 

6- 


4- 


2- 


15 


i 


£ 


i 




i 


i 




I 


i 


i 


i 




Number of individuais=6 
Number of partitions- 64 


15 


9 




1 




1 


1 


i 




o 

6 


1 

5 


2 

4 


3 

3 


4 

2 


5 

1 


6 Coffees 
0 Teas 


Figure 1. There are 64 ways in which six people can choose between tea or coffee. 


122 


PRACTICAL COMPUTING October 1983 


Statistics 


one way in which ail can choose tea, and 
only one way in which all can choose 
coffee. There are six ways — one for each 
director — - in which one chooses coffee 
while the others have tea, and six ways of 
serving one tea and five coffees. 

For two coffees and four teas you have 
to work out how many ways there are of 
picking out the two coffee-drinking 
directors. It is best done by representing 
the directors by the initial letter of their 
first names — they are called Alf, Bert, 
Connie, Dick, Evie and Fred — and listing 
them as in table 1 to whai the computer 
tells them to choose. 

The groupings in the middle column 
represent all the possible ways of picking 
out those who are to have coffee. There 
is no need to go further, for the 
arrangements are symmetrical — see 
figure 1 . 

There are 15 ways in which four choose 
coffee, six ways in which five choose 
coffee and one way in which all choose 
coffee. The total number of ways in which 
the directors can be divided into coffee 
drinkers and tea drinkers is 1 + 6 + 15 + 
20 + 15 + 6 + 1 or 64 ways. 

If all choose tea there is only one way 
out of the 64 ways that this can happen 
randomly. Their behaviour can be 
explained in two ways: 

* they really do prefer tea 

• they are choosing at random, and a one- 

in-64 event has occurred. 

It is safe to infer that their apparent 
preference for tea is genuine. On the other 
hand, there still remains the one-in-64 
chance that it Is a random choice, so unless 
you are prepared to take that risk of being 
wrong, it is wise to keep coffee on the 
menu for future board meetings. 

But what if one director had chosen 
coffee? The calculations show that there 
are six ways of this happening in a purely 
random way. You could still believe they 
prefer tea but there is a much stronger risk 
that their corporate choice was made at 
random. There is now a six-in-64 chance, 
around nine percent, that you are 
observing random choices and not real 
decisions. 

You could also arrive at the same 
conclusion if you had just witnessed the 
directors voting five to one in favour of 
investing half the company's funds in a 
new expansion project. With so many 
factors involved in the market the 
outcome is virtually unpredictable, and a 
random choice may be as good as any. 
With six directors, only a unanimous 
decision can signify anything to a mere 
outsider. 

The scene now' changes to a school 
biology laboratory where the students are 
watching six woodlice in an apparatus 
called a choice-chamber. Incidentally, the 
woodlice are also called Alf, Bert, Connie, 
Dick, Evie and Fred. They are being made 
to choose between going to a specially 
prepared damp part of the chamber or to a 
part which is dry. 


As it turns out, they all go to the damp 
part. You have not been able to ask them 
which they prefer, and before the test was 
run you did not know which they would 
prefer. You took care to design the 
apparatus so that the two sections of the 
chamber should be equal in all respects 
other than dampness, and that the 
woodlice should be put into the chamber 
at a point where they were equidistant 
from both. 

As with the directors, so also with the 
woodlice, you must have a unanimous 


decision when there are only six choosers, 
A five-to-one majority is hardly sig- 
nificant, for it could be obtained on over 
nine percent of occasions by random 
means, with no purposeful choice being 
made. 

Thinking of the same kind applies to 
any situation in which individuals are 
being offered mutually exclusive choices. 
It even applies to general elections — 
ignoring the minor parties — but here the 
electorate is so large that even a small 
(continued on next page) 


Table 1. 

How many 
choose coffee 
0 
1 

2 


Who has coffee 

no one 

A, B, C, D, E, F 

A + B t A + C, A + D, A + E, A + F, 

6 + a B + D, B + E, B + F, 

C+ D, C + E, C + F, 

D 4* E, D + F, 

E + F 

A + B -F G P A + B 4- D, A + B + E, A 4- B 4- F, 
A + C + D, A + C + E, A + C + F, 

A + D + E, A + DTF, 

A + E + F, 

B + C+D t B + C + E, B + C + F 
B + D + E, B + D + F, 

B + E + F, 

G + D 4- Ej C 4- D 4- F, 

C-FE4-F 
D 4- E 4- F 


Number 
of ways 
1 

6 

15 


20 


JO HOME : PRINT TAB l 143 'THIS OR THAT?" 

20 VTAB 5: INPUT "HOW MANY INDIVIDUALS IN TOTAL? ";N 

30 IF N £ 0 OR N } 30 THEN PRINT "NUMBER OUT OF RANGE, PLEASE RE-ENTER' 1 : GOTO 

20 

40 CALL - S 66 

50 VTAB 7: INPUT "HOW MANY IN ONE OF THE GROUPS? n ;fi 

£0 IF G < 0 OR G > N THEN PRINT 11 NUMBER OUT DF -RANGE, PLEASE RE-ENTER": GOTO 5 

0 

70 PRINT 

BO PRINT ' , CALCULATIN^ ,, 

SO IF G - N / 2 THEN P = 100* GOTO 220 
100 IF G 3 N / 2 THEN G = N - G 

no c = o 

120 FOR J = 0 TO I NT £ tN — 13 / 2) 

130 GO SUB 1000 

140 IF J = G THEN CG - C 

ISO NEXT J 

160 C - C * 2 

170 CG - CG * 2 

ISO If H / 2 = INT (N / 2) THEN NF - N / 2: GDSUB 2000 
190 C-C+L/F/F 
200 P - CG / 0 * 100 
210 C = C * F 

220 PRINT : PRINT "THE PROBABILITY OF OBTAINING A RESULT A5EXTREME OR MORE EXTR 
fiME THAN THIS IS*": PRINT i PRINT TAB f 173 INT £P 4- .5);" *" 

230 END 

1000 NF = J: GDSUB 2000 
1010 D1 - F 

1020 NF = N - J: GDSUB 2000 
1030 D2 - F 

1040 C = C + 1 / D1 / D2 
1 050 RETURN 

2000 F = is IF NF - O THEN RETURN 

2010 FOR K = I TO NF 

2020 F = K * F 

2030 NEXT K 

2040 RETURN 

3 RUN 

THIS OR THAT? 

HOW MANY INDIVIDUALS IN TOTAL? 15 
HOW MANY IN ONE 0F THE GROUPS? 4 

CALCULATING 

THE PROBABILITY DF OBTAINING A RESULT ASEXTREME OR MORE EXTREME THAN THIS IS: 

12 % 


Applesoft Basic program and sample run. 


PRACTICAL COMPUTING October 1983 


123 



A question of 
significance 

(continued from previous page ') 

majority is significant. It is when only a 

few individuals are making a choice that 

you need to assess more precisely the 

effects of random or partly random 

factors. 

Experiments in animal behaviour are 
another instance in which it is essential to 
take possible randomness into account. It 
was in this setting that tests for 
significance were first designed. You often 
have only a few animals to use, so 
randomness plays a relatively large and 
disturbing part in the result. The same 
problem arises in other kinds of scientific 
and medical experiment — even those 
which do not involve individuals making a 
deliberate choice. 

The alternative could be “does the 
patient recover or not?” or “does this 
drug kill the pathogen or not?” The 
criterion is that there must be two 
mutually exclusive outcomes with an 
apparently equal chance of either 
outcome. 

Working out the odds for a large 
number of individuals is extremely 
tedious, which is where a micro is a great 
help. You have to find out in how many 
ways it is possible to partition the 
individuals into two groups. A group of n 
individuals partitioned into two groups 
can be represented by x:y, where x + y = 


Table 2. 


Partition 

No. of ways 

0:n 

n!/0!(n - 0!) = 1 

1m - 1 

n!/1 !(n - 1 1) = n 

2:n - 2 

n!/2!(n — 2)! 

and so on down to 

n - 2:2 

n!/(n-2)!2! 

n - 1:1 

n!/(n - 1)!1 ! = n 

n:0 

nl/(n — 0)!0! = 1 


n. For example two out of six directors 
taking coffee and four taking tea can be 
represented by 2:4. 

The different partitions and the 
calculation of the numbers of ways are 
shown in table 2. 

The symbol ! means factorial. For 
example, 5! means 5 x 4 x 3 x 2 x F 
Unexpectedly, 0! is 1, The expressions in 
table 2 are all of' the form 
nl/g!(rt-g)l 

where g is the number of individuals 
making one choice and (n-g) is the 
number making the other choice. The 
micro has to work out all these terms and 
add them to find out how many different 
partitions are possible. 

Since the table is symmetrical about the 
halfway line, the micro only has to work 
out the top half and double the result. If n 
is even, there is a row halfway down the 
table for n/2:n/2. Picking out half the 
individuals in all possible ways to put into 
one group automatically picks out the 
other half to go into the other group, so 
this partitioning is added in only once. 

While the computer is summing all these 
expressions, it also sums those expressions 


w r hich refer to partitions as extreme or 
more extreme than the one being tested. If 
one of the six directors chooses differently 
from the others you need to sum the 
expressions Tor 0:6 and 0:5 and then 
double the sum. You can then work out 
the probability of getting a majority 
decision of five or more out of six 
according to the formula. 

((number of ways for 0:6 f 0:5, 5:0 r 6:0) 
(total number of ways)) x 10 percent 

The nl in the denominators of each 
quantity cancel out, so there is no need to 
evaluate it. 

Listings are provided for the Apple 11 
and the BBC Microcomputer. The Apple 

11 version requires n to be more than 2 and 
not more than 30. Calculating factorials 
greater than 33! causes an overflow error. 
Since the test is not of great interest when 
numbers are larger than 30 this is no 
disadvantage. 

N is the number of individuals observed 
and G is the number in one of the groups. 
Line 90 disposes of one obvious result 
without calculation. Line 100 converts G 
to be the number of the smaller group. 
Lines 120 to 150 run through the possible 
partitions, except equipartition when N is 
even. 

The program uses the subroutine 
beginning at line 1000 to work out the 
expression 

1fG!(N — G) ! 

for each value of G in turn, and 
accumulates their total; the subroutine 
beginning at line 2000 calculates the 
factorials required. NF is the number for 
which the Factorial is to be calculated and 
F is the factorial. In line 140 the subtotal 
of values up to and including G is 
registered as CG. 

The totals C and CG are then doubled in 
lines 160 and 170, If N is even, a value for 
the partition N/2:N/2 is then added to the 
total obtained in lines 180 to 200. Line 210 
calculates probability P as a percentage. 

The percentage is rounded off to the 
nearest whole number; if you are 
interested in long odds you could alter the 
proposal to print out any number of 
decimal places. The sample run might 
have been used to assess the results of 
asking 15 breakfasters whether they would 
prefer kipper or haddock. The fact that 1 1 
take kippers does not support the belief 
that breakfasters in general prefer kippers. 
With a purely random selection, there is a 

12 percent chance that the number 
disagreeing with the majority will be four 
or fewer, A majority of 1 1 to four means 
very little. 

Figure 2 shows that the ways in which 10 
or more people can choose coffee — or 
kippers — at random is six percent of the 
total number of ways. The program gives 
an answer of 12 percent as in line 170 it 
doubles the numbers relating to the shaded 
area before working out the percentage. 
Which result you take depends on what 
you want to know. 

If you want to know the probability of 



Figure 2. There is a six percent chance of only four people out of 15 taking tea. 


124 


PRACTICAL COMPUTING October 1983 



Statistics 


iO CLS I PRINT! AE; < 13) ’ This? - or T 
hat? " 

20 INPUTTAEU 0 rS> "How wama indiyid 
uals in total " i total 

30 IF tot&KS OR total >30 THEN PR 
INT *Nurtbar out of ranaej Please re-e 
r.ter " *GDTO20 

40 PRINTS PC ( 40 ) 

50 INPUTT AB i 0 ? 7) " Hau j^any in one 
of the drouF'S'ififou^ 

60 IF GroL>p<0 OR croup) total .THEN 
PRINT "Nuhber out of rander please r 
e-enter - iGOTOSO 
70 PRINTSFCt B0 ) 

B0 PRINT ■CALCULATING" 

90 IF Group “ total/2 THEN probab 
i 1 ity - 100 i GOTO 210 

100 IF Group > total/2 THEN Group 
33 total - droop 
110 conb = 0 

120 FOR Partition = 0 TO INTCttota 
l-D/2) 

130 conb = conb + FNf r actions < part 
i t i on ) 

140 IF partition = Group THEN gtoU 
Pconb = conb 

ISO NEXT partition 

160 conb f= conbK2 

17 0 eroupcofib = draupoonb*2 


180 IF total/2 * INT t total/2 ) THEN 
oonb - coMb + 1/FNf act < total/2 )t2 
190 probability = Graupconb/eanb*! 

00 

20 0 PRINT * PRINT " The probability of 
obtaining a result ssextrene or r>or 
e extreme than this is! “ ;pRINTTAB(9* 
16) INT < probability + *5>;" X* 

210 END 

1000 DEF FNf ract ions t parti t ion ) 

1010 “ 1/FNf act ( partition) /FNf act Ct 
o ta 1 -part i t i on > 

2000 DEF FNf act< nunber ) 

2010 IF nuhber = 1 OR number - 0 TH 
EN =1 ELSE ~ nunber *FNf act < nunber “1 ) 


4 UN 

This? - or That? 

How Many individuals in total?15 


How narty in one of the aroups?4 
CALCULATING 

The probability of abtainine a resul 
t ase^trene or rtore extr.epie than thi 
s is I 

12 X 


getting any extreme result — either lots 
more coffees than teas or lots more teas 
than coffees — then take into account 
both tails of the distribution of figure 2. 
This is the usual procedure, as there is 
generally no reason for expecting a strong 
majority. After all, you are assuming that 
people like tea or coffee equally well. If a 
majority is found it is usually explained 
away as a random occurrence by saying, 
for example; “You could have got this 
majority by tossing heads or tails: it does 
not prove that people prefer coffee — or 
kippers 11 . 

There may be occasions on which you 
believe there is a preference and are trying 
to prove it. Then you say, for example: 
“11 out of 15 choose coffee; at random, 
11 or more in favour of coffee occurs on 
only six occasions out of 100, so possibly 
this shows that there is a preference. The 
evidence is not strong, for there is still the 
six percent chance of it being a random 
result. But as figure 2 shows, the numbers 
of ways decrease sharply towards the tail 
of the distribution. If 12 choose coffee, 
the area to the right is only two percent of 
the whole. Just one more coffee drinker 
should make you feel much more secure in 
believing that coffee is preferred. 

The BBC program is in principle the 
same as the Apple version but makes use 
of the special facilities available on the 
BBC machine. The calculation of each 
value of the fraction. 

1/group!( total-group)! 


BBC Basic program and sample run. 

is performed by a function FN Fractions, 
defined at line 1010, which uses function 
FNFact at line 2010 to calculate the 
factorials. 

The total number of ways, Comb, is 
accumulated at line 130. At line 140 this 
cumulative value is assigned to the 
variable, Groupcomb, when the partition 
being evaluated is the same as the partition 
observed. Cumulative totals are doubled 
at line 190 and the single addition is made 


at line 180 in the case when the number of 
individuals is even. C 

References; 

Coffee, Tea or Me? by T rudy Baker and 
Rachel Jones. Corgi Books. 1967. 
Longman Statistical Utility by Owen 
Bishop. Longman Microsoftware, 
1983. 

Statistics for Biology by Owen Bishop, 
Longman, (4th edition 1983). 








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* Circle No. 195 


PRACTICAL COMPUTING October 1983 


125 




Check-out 

network 

At Orpington’s Walsingham School they use a Research Machines micro to simulate a 
point-of-sale terminal. Hewan Ormson explains how it’s done. 



MANY LARGER SHOPS and supermarkets are 
installing electronic point-of-sale terminals, 
POSTs, which are generally on line to a 
central computer. There are several 
different methods of data capture, 
including: keyboard input of a code 
number; optical character reader, or light 
wand; magnetic stripe reader; laser 
scanner, or bar code reader; merchandise 
ticket reader, or kimball tag. 

British Home Stores has branches in 
most major shopping areas, and they all 
have electronic POST. BBC Radio includes 
a programme in the “Computers in the 
Real World” series which examines this 
system. Each POST is connected to an in- 
store minicomputer, or an area mini- 
computer. The minicomputer holds all the 
data relating to the stock using disc storage. 
The minicomputer is joined by telephone 
line to a mainframe at BHS headquarters 
— see figure 1 . 

Everything sold in the store is given a six- 


digit code number. The prices are shown on 
the shelves rather than on each individual 
item. When a customer buys an article he or 
she takes it to a POST. The POST operator 
types in the code; the POST rinds the item 
details from ihe minicomputer and displays 
the price. The operator keys in any other 
items and the POST totals the prices. The 


operator keys in the maount of cash 
tendered, the POST displays the change 
due and prints out a receipt. 

The receipt typically contains the 
following information: the type, price and 
number of each item purchased; the total 
cost; the amount of cash tendered and the 
change given; the date, etc. The 


10 

REM 

************************ 

20 

REM 

************************ 

30 

REM 

*** 


*** 

40 

REM 

*** 

SHOP 

*** 

50 

REM 

*** 

Ver si on 1-1 

*** 

60 

REM 

*** 


*** 

70 

REM 

*** 

Demonstrate POST 

*** 

SO 

REM 

*** 


*** 

90 

REM 

*** 

By H. Ormson 

*** 

100 REM 

*** 

June 1983 

*** 

110 REM 

*** 


*** 


120 REM ************************ 

130 REM ************************ 

140 REM 

150 CLEAR 1000; DIM C ( 20) ? I* C203 * P* C20) 
160 DM BREAK GOTO 1660 
170 PUT 12,21 

180 7 n SHOP 

190 ?;?:?:?!?:? 

200 Ai6=GETiM0> 

210 INPUT “Type the date; %D$ 

220 REM *Check that only RETURN not pr 
essed* 

230 IE D*= M,< THEN PUT 11s SOTO 210 
240 REM *Read i nr data* 

250 RESTORE 

260 FOR C=1 TO 20 

270 READ C<C) , It (C> ,P* <C> 

280 NEXT C 


290 PUT 31 

300 REM *Set up display* 

310 ?:?;?: 7: 7 11 The Walsingham Su 

per store" 

320 7 " — 

h 

330 7: 7; 7“ Type the code number then p 
ress RETURN ' 1 

340 ?"-■ — — 


350 7;?" Code nos" 

360 REM *Set up coords — initialise va 
rs* 

370 X=33: Y=45: T^O: ZX=0 

380 REM *Ask -for code number* 

390 FOR C=1 TO 4 

400 PUT 22, Y, X , " I tem% STR$ (C) , 11 " : INPU 
T J 1 %C1$ 

410 REM *Erase previous incorrect entr 
y — 43 blanks* 

420 IF ZX-1 THEM PUT 22*Y,49, " 

”z2 

X“0 

430 REM *F i nd correspond! ng article* 
440 FOR 2=1 TO 20 

450 IF " ri +CIS=BTR$(CCZJ ) THEM 510 ELS 
E MEXT Z 

460 REM *Give error message, set 2X=1- 
10 blanks* 


126 


PRACTICAL COMPUTING October T 983 


Education 1 


Figure 2. 


Tliw Wo[ ncjheim Superstore 


Receipt 

7 4ULV 



691307 

1 amp 

, 

4. W 


sports beg 

1 

5-W 

421096 

light bulb 

1 

25 

&S3692 

Shirt 

1 

6.50 


Total 

£ 

17. 73 


Cacb 

£ 

20.00 


Change 

£ 

2.27 


Figure 4, 



minicomputer keeps a record of all items 
sold. This information is automatically sent 
to the mainframe each evening* Further 
details of the system, follow-up notes and a 
filmstrip are available from BBC 
Publications. 

The program listed complements the 
(continued on next page) 

0 PUT 22, Y+i , 40, "Code number wrong, 
y again" 

0 PUT 22 ^,39*" 

0 ZX=I : GOTO 400 
0 REM *Prirtt code & article* 

© PUT 22,Y,49, I$m s PUT 22„Y,63,"1 IJ : 
IT 22j, Y, 65, F$ t Z ) 

5 REM *38 bl anks* 

0 PUT 22, Y+l , 40, " 

41 

0 REM increase total & Y coord* 

0 Y= Y+ 1 s T=T + VAL ( P$ ( Z ) ) iT*(C)=T$ (Z) :T 
<C)=F$CZ) sT(C)-CtZ) 

10 NEXT C 

0 PUT 22,50,57, "Total " 

0 T=INT (T*100> / 100 
0 L=T 

0 REM *Add trailing zeros etc* 

O GOSUB 1350 

0 REM *Print total in correct posit i 
* 

0 IP LEN(A1*)^6 THEN PUT 22, 50, 64, A1 
GOTO650 

0 PUT 22,50,65, Al* 

0 REM *Ask for cash* 

© PUT 22*52,57, "Cash? INPUT" 1 *, C 

H$ 

0 IP CASH$="" THEN 650 

0 REM #Check input Tor alpha char act 


Figure 3* 


er s* 

680 FOR 81 = 1 TO LEN (CASHS) 

690 IF ASC C M I D $ ( CASHS , Bi , 1 ) > >57 OR ASC 
(MID$(CASH*;,Ri, 1) X46THEN PUT 22,52,36 
, "Use numbers only 
" : GOTO 650 
700 NEXT Bl 

710 CASH=VAL(CASH$) :CASH=INT( (CASH+,00 
3 >* 100 ) /100 

720 REM *Output cash in correct posit! 
on 

730 L=CASHs GOSUB 1350 

740 IF LEN(A1S)=5 THEN Al*=“ "+A1* 

745 REM *erase previous entry — 40 bla 
nks* 

750 PUT 22,52,36," 

tl 

760 PUT 22.52,57. "Cash ":?;AI* 

7 70 REM -if Too much cash offered?* 

780 IF CASH <=99.99 THEN 830 

785 REM *erase previous entry - 30 bla 

nks* 

790 FUT 22,52,57," 

VI 

800 PUT 22* 52, 36, " Too much. Try again 
»! 

810 GOTO 650 

820 REM Calculate change* 

(listing continued on next page) 


PRACTICAL COMPUTING October 1983 


127 


Education 1 


(continued from previous page) 

Radiovision program, but it can be used on 
its own to supplement work on computers 
in shops — see figure 2 + It is written for a 
Research Machines 380-Z or 480-Z and 
simulates a POST used in British Home 
Stores. It occupies about 4K. 

Pupils choose four items from the list in 
figure 3 and key in the code numbers. The 
screen displays the code, the item 
description and its price. It totals the prices 
and asks For the amount of cash tendered; 
the maximum allowed is £99.99. The 
amount of change due is displayed and an 
itemised receipt is printed — see figure 4. 
The program checks for illegal code 
numbers, too much or too little cash, 
alphabetic instead of numeric input, and 


adds trailing zeros. In order to do all this 
code numbers and cash are entered as 
strings. 

Twenty items are included in the data. 
This can be increased or decreased as 


required. The code numbers are random 
numbers as generated by a 380-Z. They 
could be improved by making the first two 
or three digits represent a particular 
department and the last a check digit. C 


Variable 

Description 



CL) 

item code number, six digit 

C1$ 

inut code number 

ISO 

item name 

T 

total of goods purchased 

PSO 

item price 

T$<) 

item j stored here 

A$ 

wait/trap key presses 

T1$()} 

price \ ready for 

D$ 

date 

T() J 

code) printing 

B1 j 


L \ 

temporary store used in 

c > 

loop counters 

A1$ / 

trailing zero routine 

Z 


CASHS 

amount of cash tendered 

X,Y 

co ordinates of item on screen 

CASH 

value of CASH$ 

ZX 

count: if 1 erase incorrect entry 

CH 

change to be given 


(listing continued from previous page) 

B30 CH^CABH-T 

840 REM ^Remove any rounding errors* 
850 CH=INT< ( CH*. 001 )*100>/i 0O 
860 IF CH<.01 AND CH>=. 009 THEN CH-.01 
; GOTO 910 

880 REM *Check for boo little cash* 

890 IF CASH<T THEN PUT 22,52*36, "Not e 
nough cash. Fr y again 

" ELBE 910: REM *22 blanks* 

900 PUT 22* 52*65: INPUT"", CASH*: GOTO 68 
0 

910 PUT 22*53,65* " 11 

920 TF CH< 1 THEN CHS=STR* CCH) : CH*=LEFT 
*(CH*,4) :CH=VAL(CH*) 

930 REM *Add trailing zeros etc* 

940 REM *8utput change in correct posi 
tion* 

950 L=CHs 60SUB 1350 

960 IF LEN (Al*) =5 THEN Ai$=" "+A1* 

970 PUT 22*54,57* "Change %A1* 

980 PUT 22,55,65," “ 

990 REM *Print receipt* 

1000 LPRINT "The Walsinghare Superstore" 
1010 LPRINT : LPR I NT "Receipt " l D* 

1020 LPRINT 
1030 FOR C=1 TO 4 

1040 LPRINT T(C) ; TAB (10) ; T*(C> StTAB<27> 

. M 1 Mb 
3 1 9 

1050 IF LEN(T1*)=6 THEN LPRINT TAB <301 
5Tlt(C) ELSE LPRINT TAB (31 > ; T1 * ( C> 

I960 NEXT C 
1070 LPRINT 
10S0 L=T 
1096 BOSUB 1350 

1100 LPRINT TAB (20) ; "Total " ; TAB (27) \ "£ 

IF m 

1110 IF LEN ( A14 ) =6 THEN LPRINT TAB(30> 

;A1* ELSE LPRINT TAB(31)!A1S 

1120 LPRINT 

1130 L=CASH 

1140 BOSUB 1350 

1150 LPRINT TAB (21 ) ; "Cash" ; TAB (27 ) S "£" 
5 

1160 IF LEN(A14>=6 THEN LPRINT TAB (30) 
;A1* ELSE LPRINT TAB(31);A1* 

1170 LPRINT 
1180 L=CH 
1190 BOSUB 1350 

1200 LPRINT TAB (19); "Change TAB (27); " 

£f) * 

1210 IF LEN ( A1 $) =6 THEN LPRINT TAB (30) 
;A1$ ELSE LPRINT TAB(31>;A1* 


1220 LPRINT 
1230 LPRINT' 


Thank you for your custom 


1240 LPRINT 

1250 LPRINT" Please call again 1 
1260 LPRINT: LPRINT: LPRINT 
1270 PUT 12 - 

1280 2 11 Take your receipt" 

1290 


1 300 A*-GET* (200) : ? : ? 

1310 ?" Is there another customer? <Y/N 
) " : A$“GE T* (0> : A*=GET$() 

1320 IF A*— 11 V" OR A$="y" THEN 250 
1330 IF A$="N" OR A*="n" THEN 1660 ELS 
E PUT 11:80101310 

1340 REM ^Subroutine for adding traili 
fig zeros 

1350 A1*=STR*CL) :L1=LEN(A1*) : J=INT(L) 
1360 IF Ll>=6 THEN 1430 

1370 IF L 1=5 AND MID$(A1$*3* 1)0", " TH 
EN A1 S=A1 4+"* 0“ ± GOTO 1430 
1390 IF LI =4 AND J=0 THEN Al$=" 0"+RIG 
HT$(A1S*3) ; GOTO 1430 

1390 IF L 1=4 THEN A1 $=A1 $+"0" : GOTOl 430 
1400 IF L 1=3 AND MID* <A1*,2* 1 > = " . " THE 
430 

1420 IF LI =2 THEN A1 *=A1 $+ " . 00" 

1430 RETURN 

1440 REM *Data - code no, item, price* 
1450 DATA 943303* pi ug, " 0.45" 

J 460 DATA 185233^, toothpaste, " 0.39" 
1470 DATA 246717, shampoo, " 0.40" 

1480 DATA 243304, blouse* " 4. 75" 

1490 DATA 663303, sports bag," 5.99" 
1500 DATA 421096, light bulb," 0.25" 
1510 DATA 174603, shoes, 12.99 
1520 DATA 276508* gl oves* " 3-00" 

1530 DATA 1 91949* socks, "■ 0.57" 

1540 DATA 691307* lamp* " 4.99" 

1550 DATA 705S69, clock* 12.99 
1560 DATA 636274* annual * " 1.50" 

1570 DATA 837350* football book*" 2.25" 
1580 DATA 697261, doll , " 3.75" 

1590 DATA 653692, shirt, " 6.50" 

1600 DATA 366890, scarf 4.20" 

1610 DATA 605466, handkerchief , " 0.30" 
1620 DATA 504696* night dress* « 8.50" 
1630 DATA B04379, toy car," 1.75" 

1640 DATA 382036* pyj areas* " 6.30" 

1650 REM *Fi ni shed* 

1660 PUT 12,23 
1670 END 


128 


PRACTICAL COMPUTING October 1983 


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PRACTICAL COMPUTING October 1983 


129 


I RECENTLY had to write a program to deal 
with responses to sales enquiries for a 
large engineering firm. Among other 
information the reply was to include the 
names of a local dealer, the area sales 
representative and satisfied users of the 
equipment in the area. Clearly a 
geographical key was required to identify 
which dealers, reps and users were most 
appropriate. 

Most business letters include the 
postcode in their address, which can form 
the basis of a geographical sort. Reading 
from left to right, the structure of the 
postcode is as follows: 

+ one or two alpha characters denoting 
the area; there are 120 areas in the U.K. 

• one or two numeric characters 
followed by a space, to specify the district; 
there are 2,700 districts in the U.K. 

• one numeric character to specify a 
sector; there are 8,900 sectors in the U.K. 

• two alphabetic characters to denote a 
street or part of a street; there are 1,5 
million in the U.K. 

• occasionally the district code contains 
an alpha as well as a numeric character 
before the space. 

This somewhat flexible construction of 
the postcode requires care in pro- 
gramming to ensure that as many errors as 
possible in operator entry are catered For. 
Figure l shows a flowchart for a simple 
basic program for entering postcodes. 
Each character is examined as it is entered 
and is accepted or rejected as appropriate. 

The only operator instruction that has 
to be given is to insert a space to denote the 
end of the first section of the postcode if it 
contains only one numeric character; the 
space is inserted automatically if it 
contains two numerics. The postcode, 
area, district, sector and street are stored 
as strings C$(l), C$(2), CS(3), C${4) so 
that further validation can take place and 
to simplify their use as sorting keys. 


Postcode 
sort key 

Geographical location is the key to sorting your sales 
information, says John Locke. 


In Ehe simplest case the post area is 
sufficient as a first sort key. If a large 
number of disc-stored records have to be 
processed, then selection rather than 
sorting will increase the speed of operation 
by up to N/n, where N is the total number 
of items and n is the average number 
selected . The 120 area codes can be stored 
as an array in the program, so that CY$(1) 
is AB and CY$(120) is ZE. 

Random-access disc Files are also set up 
for postcode cross-reference, dealer 
information rep information, satisfied 
user information and product 


200 


Clsar screen. 

Print 

"Enter postcode" 
Initialise postcode 
Group {Z = 1J, 

Turn on cursor. 



information. The postcode cross- 
reference file has record numbers 
corresponding to the postcode array 
number in memory. Each record contains 
the record numbers of dealers covering 
that area, and the rep for the area* It is 
assumed that there are no more than three 
satisfied users in each area. 

An operator who wishes to input an 
enquiry selects from the main menu and 
then enters the product number and the 
postcode of the enquiry. Product details 
are accessed directly from the product 
number. The area part of the postcode 
C$(l) is then matched to the array CT$(X) 
by: 

FOR X — 1 TO 120: IF C$(1) < > CY$(X) 

THEN NEXT X 


Print 

Backspace 




Print 

Character 

i 390 


f 360 

Reduce 

C3{z) by One 
Character 




Add 

Character 

To CS(2) 


z=z+i 


Figure 1. Flowchart for postcode program. The box numbers refer to the program lines* 


130 


PRACTICAL COMPUTING October 1983 


Programming 


The loop is exited with the match 
number X, which is then used to access 
directly the postcode record. This in turn 
is used to access the rep information and 
all relevant dealer information. Up to 
three satisfied users are always used for an 
area, so the Satisfied Users file can be 
accessed for record numbers from 3X — 2 
to 3X, 

In this simple example, a printout can 
be made of enquiry number, postcode, all 
applicable dealers, names and addresses 
together with further selection infor- 
mation such as their sales and credit 
ratings, exclusion from certain products, 
etc., and up to three satisfied users’ names 
and addresses. This list can be pinned to 
the original enquiry letter for the sales 
staff to make their selection of one dealer 
and one user. Alternatively, further 
automatic selection can take place. In 
either case, to output a sales letter only the 
enquirer’s name and address — if not 
already stored — the product, dealer, rep 
and user numbers need to be inserted. 

While the dealer file is being 
constructed, the postcodes covered by 
each dealer have to be inserted in the 
postcode cross-reference file so that these, 
through the array match, will write the 
dealer number in the first vacant field of 
that postcode record. Amendment and 
deletion of dealer records must also access 
and modify these fields. The whole 
process is complex but routine. It slightly 
slows entry, amendment or deletion of 
dealer data, but is not a significant 
overhead as sales enquiries are answered 
more often than records are updated. 

A great deal of detail is available from 
the Post Office on postcodes, ranging 
from the complete address file on 
magnetic tape for £15,000 down to 
publications on post towns, valid sectors, 
etc. Magnetic-tape file extracts are 
available from £4.75 per thousand 
records, subject to minimum charges. 
Post zone files of codes and Ordnance 
Survey grid references are available from 
£6,000 on tape. Postcode maps are avail- 
able from J Bartholomew Sc Sons Ltd, Geo- 
graphia Ltd, and Postal Headquarters, 

There are also advantages in sorting 
outgoing mail when bulk posting is used. 
The Post Office gives a rebate on bulk 
posting of second-class mail that has been 
pre-sorted according to post code. For 
example, 5,000 to 23,529 letters are given a 
15 percent rebate on the postage paid if 
they are pre-sorted. These levels are shown 
in the Inland Compendium held by main 
post offices. 

The level of rebate is dependent not only 
on the total number of letters mailed but 
also on the amount of pre-sorting carried 
out. A booklet will be available shortly 
from regional offices and head 
postmasters giving more details. The Post 
Office’s Post Code Marketing Section 
emphasise the importance of involving the 
local Post Office in proposals for bulk 
posting at an early stage, [Tj 



Figure 2, Most business letters include the postcode in their address which can form the 
basis of a geographical sort. 


Postcode listing. 

200 CLSs PR1NT"ENTER POSTCODE" : 1 = 1 : 

PRINTCHR$U4> : F0RX=1T04 : C$ < X > =" “ sNEXTX 

210 Z$=INKEY$: IFZ$=" "THEN210 

220 IFASC< Z$) > 64ANDA5C<Z$) <91 THENGOTO2E0 

230 IFASC<Z$)>4QftNDftSCt:Z$) <5STHENGOTO320 

240 IFZ$”CHR$(S) THENGOTQ 390 

250 IFZ$=CHR$C32)ANDZ=2THENZ=3:PRINTZ$S : 

GOTO210 

2S0 IFZ=2ORZ=3THENGOTO210 

270 IFLE!\KC$CZ)) <> 2THENGDTO3E0 

2Q0 Z=Z + 1 s I FZ <> 5THENGOTD210 

230 PRINT! PRINT" POSTCODE= " ; C$ < i) +C$ C2> 

+CHR$ < 32 > +C$ < 3 ') +C$ C 4 ') 

300 I NPUT" IS THIS CORRECT" * K$ ! IFK$=" Y" 

THENK= 1 ELSEI FK$="N 11 THENK=2ELSEPR I NT" ENTER 

’Y’ OR ’N’ ONLY" :OOTO300 

310 ONKGOTO410, 200 

320 I FZ=1ANDC$ < 1 ) <) “"THENZ=2 

330 IFZ 0 2ANDZ <) 3THENGOTO210 

340 IFZ-3THENGOTD370 

350 IFLENCC$<2) > > 1THENPRINTCHR$<32) ;:Z 
=3 ! GOTO3S0 

3S0 PRINTZ$ ? s C$<Z) =C$<;Z) +Z$: l'FLEN(C$<4) ) 

=2THENOOTO2S0EL5EGOTO2 1 0 

370 I FLEN < C$ < 3) > > 0THENGDTO2S0 

3S0 PRINTZ$; : C$ C3 J =C$ < 3) +Z$ ! GOTO2S0 

390 PRINTCHR$<S) ; : X=LENCC$<Z> > : IFX-1=0 

THENC$< Z ) =" " iZ=Z-l :GQTO210 

400 C$<Z>=LEFT$<C$<Z) , X-l> :GOTQ210 

410 END 


PRACTICAL COMPUTING October 1983 


131 


. 



• Britain’s No 1 range of products 

• Check our UK dealer network for your nearest outlet 

• After sales, speedy service from our own factory and engineers 


It’s our aim to provide satisfaction at the sign of the Big ‘M’. By providing local distributors, best prices 
and service, we offer you the most. If you don’t see it in our ad., ask your local distributor, or write to our 
Head Office for full list. 


AH prices include VAT, 

All prices correct at time of going to press, but, subject to change. 

All products normally in stock but to prevent a wasted journey phone your local dealer first before 
calling. 


132 


PRACTICAL COMPUTING October 1983 







Gjjhjr 

j 


HARDWARE 
A full colour 32k ROM 
computer with 7 text 
and graphic modes up 
to 640 x256 graphics 
and 80 column text 
screen, extended 
microsoft basic, built- 
in assembler, 1 MHz 
and tube interface, 
sideways ROM, RS423, 
A/D converter. 


BBC Model B 

MM PRICE £399 

BBC Model B+ 
Econet 

MM PRICE £446 

BBC Model B+ 
Disk Interface 
(fitted) 

MM PRICE £469 

BBC Model B+ 
Disk InterfaceH- 
Econet (fitted) 

MM PRICE £516 


PROFESSIONAL 

WORD 

PROCESSING 

PACKAGE 

BBC computer with 
disk interface, 100K 
disk drive, green 
screen monitor, 
daisy wheel printer, 
word processing 
ROM, complete 
with all cables, 
manuals, paper and 
formatting disk. 
MM PRICE £1299 


• Circle No. 174 


PRACTICAL COMPUTING October 1983 


133 





STAR DP 

The most cost 
quality matrix printers 
to be launched this year 

r 

* Friction and tractor feed*, 
plus roll holder as standard 

% 100 cps 
% Bidirectional logic seeking 
%9 x 9 matrix— true descenders 
*2.3K buffer as standard 
*Hi-res bit image + block graphic 
printing modes 

* Sub and superscripts 

* Italic printing 


*Auto underlining 
*2K user definable ROM 
^Vertical and horizontal 
*Left and right margin set 

* Skip over perforation 

* Back space Self test 




SHINWACTI 
CP80 

* Friction and tractor 
feed as standard 
*80 cps 

*Bi-directional logic 
*True descenders 
*Hi-res bit image + block 
graphic printing modes 
•X*Sub and superscripts 
■Jt Italic printing 
•JfrAuto underlining 
^Condensed and 
emphasised printing 


■fc Expanded and 

double strike printing 
•JfCompact lightweight 


134 


PRACTICAL COMPUTING October 1983 



COMMODORE 



SRECIAL 


Use this coupon to get 
£3 OFF even b etter value at your 

uroruncrc local Bi 9 ‘ M> distributor. 
^JH£rir?£z Check our list for your 

OVER £75 nearest store. 


Management distributor. The bearer is entitled to 
a £3 reduction on purchases over £75. Only one 
coupon per person can be redeemed. 

Valid until 30 November 1983. 

Micro Management, 16 Princes St, Ipswich. 

PC 


16-48K, colour, high resolution 
graphics 240 X 200, text 28 + 40, 
pre-programmed sound, user- 
defined keyboard/graphics, non 
touch-sensitive keyboard, 
microsoft type basic with 
powerful extensions, RGB/UHF, 
standard cassette interface, 
parallel printer output, several 
periferals available, printers 
available, modems and PRESTEL 
(coming). 

ORIC-1 48K 

PRICE £139.95 

ORIC-1 16K 

PRICE £ TELEPHONE 


COMMODORE 64-64K RAM, 
colour, sophisticated ROM/RAM 
user, full business applications, 
disk drives available, sound, 
UHF/composite video, proven 
basic language, exceptional 
value, high resolution graphics, 
many “add-ons” available, 
printers. 


COMMODORE 64 
PRICE £229.00 

CASSETTE UNIT 
PRICE £44.95 

DISK DRIVE 1541 
====* PRICE £229.00 

PRINTER 1515 
iPlS= PRICE £230.00 


JOYSTICK 1311 
Jtf^. PRICE £7.50 


PADDLES 1312 

PRICE £13.50 


• Circle No. 175 


PRACTICAL COMPUTING October 1983 


135 











DRABON 

DRAGON 32 

32K RAM, colour, extended 
basic, sound 5 octaves 255 tones, 
vast software range, typewriter 
keyboard, standard cassette 
drive, high resolution graphics. 
256 x 192, text 16 + 32, looks like 
a British worldbeater. 

=rHjT=, PRICE £174.99 


JUPITER 
JUPITER ACE 

3K RAM, the Forth specialist, 
basic coming. Forth language 
excellent, for serious educational 
and scientific purposes, standard 
cassette. 

PRICE £69.95 

64K RAM, colour, basic, almost 
"Apple c omp alible", 

==#1, PRICE £201.25 

JOYSTICKS 

PRICE £10.35 

KEYBOARD 


LYNX 


LYNX 96K 

PRICE £299.#9 

JOYSTICK 

INTERFACE 

PRICE £13.95 

SERIAL 

INTERFACE 

PRICE £3.99 

CENTRONICS 

INTERFACE 

PRICE £49.95 


ciurijif 

SPECTRUM 

16K and 48K, basic, colour, text 
and graphics, vast range of 
software including education, 
printer, built-in speaker. 

You can build a very good 
system at a very good price. 

ZX SPECTRUM 48 


JM, PRICE £129.95 
ZX SPECTRUM 16 


ZX81 

IK RAM. world's largest- selling 
computer, 16K expansion pack, 
masses of software, basic 
language, many expansions 
including keyboard/memory / 
printer, high resolution graphics 

£39.95 

PRICE £29.95 
ZX PRINTERS 
(NO PSU) 

PRICE £39.95 
SINCLAIR 
SOFTWARE - 
SEND FOR LIST 


WORK STATION 

Designed to lake computer, disk 
drive, printer and paper. 
Robustly built for school, 
business or home use. 

PRICE £138. 


COLOURCENIE 

16K RAM, colour, full size 
keyboard, high resolution 
graphics, semi-compatible with 

npDcnn 

COMPUTER 

PRICE £193.99 
PRINTER 
INTERFACE 

PRICE 


LYNX 48 

48K standard, expandable to 
192K, colour, 57 key typewriter 
keyboard, CP/M compatible, 
serial port, high resolution 
graphics 26S / 248, digital/ 
analogue sound converter, RGB/ 
UHF composite video, RS232/ 
parallel, cassette. 

,#=% PRICE £224.99 

disk driv es — 

100K SINGLF 
PRICE 
200K_SINGLI 
=== PRICE iiI41.su 
400K SINGLE 

PRICE £396.75 

800K DUAL 
Jtft: PRICE £71 1.85 


16K/48K RAM, colour, basic, high 
resolution 320 x 192, excellenl 
games machine from the video 
market leaders, text 24 + 40. 
serious software tor education 
and business now available. 


PRICE £299.95 

ATARI 400 


PRICE £149.95 

ATARI DISK DRIVE 


JWfc PRICE £299.00 


136 


PRACTICAL COMPUTING October 1983 


PRINTERS 

SEIKOSHA GP100 
PUCE £214.99 

SEIKOSHA GP250 
JM: PUCE £276.00 

NEC PC 8023 (D/M) 

PRICE £368.00 

EPSON MX 100 
JM: PRICE £488.75 

EPSON RX-80 

PRICE £339.25 

EPSON FX-80 160cps 
PRICE £454.25 

SPARK JET PRINTER 
PRICE £419.75 

SMITH CORONA D/WHEEL 
M PRICE £511.75 

TEC STARWRITER 40cps 
^lin. PRICE £1265.00 

JIUK 6100 D/WHEEL 

PRICE £458.85 

STAR MUP4 GRAPHICS 
^1§= PRICE £171.35 



RGB COLOUR STD/RES 


PRICE £287.50 

RGBCOLOUR H/RES 
=== PRICE £632.50 

12" GREEN MONITOR 
PRICE £95.52 

12" AMBER MONITOR 


PRICE £120.75 



Think you’re good enough to 
become a Big W distributor? 
Full back up given. Write for 


details and application forms to 

Steve Macfarlane 
Micro Management 
16 Princes St, Ipswich 
Tel: (0473) 219461 


* Circle No. 176 



MICRO MANAGEMENT 


Head Office: 16 Princes St. Ipswich 0473 219461 


Ilfracombe 

Bits & Bytes 

44 Fore St. 027162801 

Ipswich 

Micro Management 
32 Princes St. 0473 59181 

K^ing Eton -on-Thame s 

Vision Store 

3 Eden Walk 01 549 4900 

Lichfield 

Fosters 

59 Tamworth St. 06432 22341 

Liverpool 

Beaver Radio 

20/32 Whitechapel 051 709 9898 

London 

Computers of Wigmore St. 

87 Wigmore St,Wl 01 486 0373 

P ere i vale 

8S High St North, East Ham, E6 
01 472 8941 

Trend Video & Hi Fi 

167 High St, E17 01 521 6146 

Northampton 

Richard Reeves 
1 74 Kettering Rd 0604 33578 

Norwich 

Richard Pank 

Anglia Square 0603 27963 

Plymouth 

Syntax Ltd 

46 Cornwall St 0752 28705 

The Model Shop 

11 Old Town St. 0752 21851 

Shetland 

Tomorrows World 
Esplanade, Shetland 0595 2145 

S outhend -on- Se a 

Estuary Software 

261 Victoria Ave. 0702 43S68 

Stevenage 

Video City 

45/47 Fisher Green Rd, 53808 

Stroud 

The Model Shop 
22 High St. 04536 5920 

Surbiton 

Computes olve 

8 Central Parade, St Marks HiH 
01 390 S 135 

Taunton 

LA Gray 

1 St James St. 0825 72986 

West Bromwich 

Bell & Jones 

39 Queens Square. Sand we II Centre 
021 553 0820 

Woking 

71 Commercial Way Jii 

04862 25657 4 %J 


Abergele 

Abergele Computer Centre 
8 Water St. 0745 826234 

Ballymoney 

Everyman Computers 
Charlotte St, 02666 62116 

Bedford 

The Software Centre 
S2aBromhamRd 0234 44733 
Birmingham 

The Software Centre 
80 Hurst St, B5 021 622 2696 

Blackburn 

Microwise, Conliffe Road 
W h ite burch E st ate 0 254 67 8933 

Bodmin 

Microtest Ltd 

18 Normandy Way 0208 3171 

Bridgend 

Automation Services 

31 Wernlys Ed, Penyfai 0656 720959 

Bristol 

Brens all Computers Ltd 

24 Park Row 0272 394188 

Bromley 

Data store 

6 Chatterton Rd. 01 460 8991 

Bury St Edmunds 

Bury Computer Centre 
Guildhall St. 0384 705772 

Cambridge 

GCC (Cambridge) Ltd 

66 High St, Sawston 0223 835330 

Chelmsford 

Essex Computer Centre 
Moulsham St. 0245 338702 

Clacton-on-Sea 

Clacton Computer Centre 
Pier Avenue 0255 422644 

Colchester 
Emprise Ltd 
58 East St, 0206 865926 

Coventry 

Coventry Micro Centre 
33 Far Gosford St. 0203 58942 

Gloucester 

The Model Shop 
79 Northgate St. 0452 410693 

Great Yarmouth 

Criterion Computers 
12 George St. 0493 53956 

Guildford 

The Model Shop 
23 Swan Lane 0 483 39115 

Hastings 

The Computer Centre 
37 Robertson St. 0424 439190 

Hay-on-Wye 
The Playpen 
Market St. 0497 820129 

Hemel Hempstead 

Faxminster 

25 Market Square 0442 55044 

Holyhead 

P & K Computers * 

33 Williams St, 0407 50383 

Hull 

Computer Centre (Humberside) 

26 Anlaby Rd. 0482 26297 


PRACTICAL COMPUTING October 1983 





MkroValuc 


80-BUS MULTIBOARDS 


GM811-CPU Board 

*4MHzZ80ACPU 

* 4 'Bytewide’ Memory Sockets 

* 2xB-BltlnpuffOutput Ports 

* 8 Bit Input Port 

* RS232 Serial Interface C40C 

* Cassette Recorder Interface AP 


MP826— Static RAM 
Board 


* 32K Static RAM 

* Battery Backup 

* Page Mode Ope rati on 


£185 


GMS13-CPU/64K RAM 

Board 

*4MHzZ80AOP<U * 64K Dynamic RAM 

* RS232 ! ntertace * Two 8- Bi t ! IQ Ports 

* Cassette Interface 

* Extended St Page Ad dress I ng Modes 

* CPJM Compatible 


Monitor 


£225 


GM812-Video 
Controller Board 

■! 80 Character$x25 Line Display Format 

* On-board Z80A Microprocessor 

* Buffered Keyboard input 

* Programmable Character Generator 

* 160x75 Pixel Graphics m ^ 

* Light Pen Input Si 1 JL J 


GM803-EPROM/ROM 

Board 


* Up to 40K of Firmware 
*2708 or 2716 EPROMS 
Page Mode Ope ratio ns 


£65 


GM802— 64K RAM 
Board 


* 64K Dynamic RAM 

* 4MHz Operation 

* RAM Disable Function 

* Page Mode Ope rati on 


£125 


GM816— Multi I/O 
Board 

* 6 I/O Ports 

* 4CounteriTimerChannels 

* On-Board Real Time Clock 

* Battery Backup 

* Further Expansion C40R 

Capability 3i 149 


PLUTO -Colour 
Graphics Board 

* On- Boa rd 16 B 1 1 M 1 c ro p roc essor 

* 640x576 Bit Mapped Display 

* 192K Of Dual Ported RAM 

* Comprehensive 
On-Board Software 


£399 


CLIMAX-Colour 
Graphics Board 

* 256x256 Pixel Display 

* 16 Col ou rs 

* Ultra-fast Vector fit 
Character 
Generation 

* Light Pen Input 

* UHF or RGB Outputs 


UHF Version 

£199 

UHF & RGB Version 

£220 


EV814— IEEE488 (GPIB) 
Controller 


* Cost Effective Controller 

* Comprehensive Software 
Supplied 

* Full Implementation 

* Easy To Use 


£140 


GM827-87Key 

Keyboard 

* User Def I nable Function Keys ^ M 

Numeric Keypad fflfi 

* CursorControl Keys 


GM839- Prototyping 
Board 

% Fibreglass RC.B, 

* 80-BUS Signal Identification 

* High Density 1C PA 

Capability SilAeOU 


All the boa rds and components in the 80-BUS 
range are fu I ly compatible and offer a very 
flexible and cost effective solution to your 
computer needs. For further Information about 
the 60-BUS range contact your nea rest 
MICROVALUE dealer 


GM829-Disk 
Controller Board 

* Up To 4 Mixed 5,25 &8 J ' Drives 

* SASI Hard Disk Interface 

* Singled Double Density Operation 

* Singled Double Sided Drive Support 

* Supports 48 and 


96 TPI Drives 


£145 


GM833-RAM-DISK 

Board 


* Virtual Disk Operation * 512K Dynamic RAM 

* Port Mapped For Easy 1 nte rta c e Softwa re 

* Over lOTImes Faster 
Than a Floppy Disk 

Please note: This board cannot be used osa 
conventional RAM board 


£450 


138 


PRACTICAL COMPUTING October 1983 





MkroValuc - MkroValuc 



COMPUTERS 

i Galaxy 2 

“I would place the Galaxy at the top of my list" 

(Computing Today, April 1983) 

★Twin Z80A Processors ★Serial and parallel printer 


★CP/M 2.2 Operating 
System 

★64K Dynamic RAM 

★ 800K Disk Capacity 

★ 80x25 Video Display 


interfaces 

★ Cassette and light pen 
interfaces 

★ User definable function 
keys 

★ Numeric key pad 

★ 12" Monitor included 


£1495 



At last-a Winchester Drive 
for your Gemini /na/com System! 


GM835 Winchester Drive Sub-system. 

★ 5.4 Megabyte Formatted Capacity 

★ Rodime Drive 

★ Industry Standard SASI 
interface 

★ Integral Controller 
and power supply 



Phoenix 
PI 2 Monitor 


A high quality data display 
monitor, ideal for all Nascom 
and Gemini systems. 

20MHz resolution. 

Available in amber or 
green phosphor. 


£110 


BUY FROM THE 
COMPUTER 
PROFESSIONALS 


MiCROVALUE 

DEALERS: 

AMERSHAM, BUCKS 

Amersham Computer Centre. 
18Woodside Road. 

Tel: (02403) 22307 

BRISTOL 

Target Electronics Ltd., 16 Cherry Lane. 
Tel: (0272)421196 

EGHAM, SURREY 

Electrovalue Ltd., 

28 St. Judes Road, Englefield Green. 
Tel: (07843) 3603 


Disk System for Gemini & na/com 

GM825 Disk Drive Unit - The GM825 floppy disk housing is supplied with either one or two 
5.25" single sided, double density, 96TPI high capacity Micropolis 1015F5 disk drives. 
These provide 400K bytes of formatted storage per drive. (Gemini QDSS format). The 
CP/M2.2 package available supports on-screen editing with either the normal Nascom 
or Gemini IVC screens, parallel or serial printers . 

An optional alternative to CP/M is available for Nascom 
owners wishing to support existing software. 

Called POLVDOS 4. it includes an editor and assembler 
and extends the Nascom BASIC to include disk commands. 


CP/M2.2 Package 

(GM 532 for Gemini) 


£90 


Single Drive System 

GM825-1S 

£350 

Dual Drive System 

GM825-2S 

£575 

SOFTWARE 

CP/M Software 
Compas 

is totally different from other 
compiler based Pascal 
systems, as it allows you to 
create, edit, run, and 
debug Pascal programs 
In a highly interactive 
manner. 


POLYDOS 4 

for Nascom 




‘The Last One’ is used in conjunction 

with Microsoft’s MBASIC* No knowledge of 
BASIC programming is required since all input 
is performed using question f '2'in 

and answer routines written 
In plain English. 

•MBASIC-MicroValue Price If purchased with 

The Last One’ -£178.95 Inc.VAT 


IPSWICH 

MDW (Electronics). 

47/49 Woodbridge Roaa East. 

Tel: (0473) 78295 

LEEDS 

Bits 8c PC’s, Leeds Computer Centre, 
62 The Balcony, Merrion Centre, 

Tel: (0532)45887 

LONDON W2 

Henry's Radio, 404 Edgware Road. 

Tel: 01-402 6822 

LONDON SW11 

OFF Records. 

Computer House. 58 Battersea - Rise, 
Clapham Junction. 

Tel: 01-223 7730 

MANCHESTER M19 

EV Computing, 700 Bumage Lane. 

Tel: 061-4314866 

NOTTINGHAM 

Computerama, (Skytronics Ltd.) 

357 Derby Road. 

Tel: (0602) 781742 

Telephone orders welcome 


£120 


Gemini 

Software: 

(All prices ex-VAT). 


GEM PEN Text Editor £45 

GEM ZAP Assembler £45 

GEM DEBUG Debugging Utility £30 
WORDSTAR Word Processor £295 
GEM GRAPHIC Links with MBASIC £35 


MkroValuc 


REAL value — from the Professionals 


• Circle No. 177 


PRACTICAL COMPUTING October 1983 


139 




H ow cfo you stay up-to-the-minute with 
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The latest innovations The new 

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140 


• Circle No. 178 

PRACTICAL COMPUTING October 1983 



Open file: BBC 


Open 

File 

This regular section of 
Practical Computing 
appears in the magazine 
each month , incorporating 
Tandy Forum, Apple Pie, 
Sinclair Line-up and other 
software interchange 
pages. 

Open File is the part of 
themagazinewrittenbyyou, 
the readers. All aspects 
of microcomputing are 
covered, from games to 
serious business and 
technical software, and 
we welcome contributions 
on CP/M, BBC Basic, 
Microsoft Basic, Apple 
Pascal and so on, as well as 
the established categories. 

Contributors receive 
£30 per published page 
and pro rata for part 
pages, with a minimum 
of £6. Send contributions 
to: Open File, Practical 
Computing , Quadrant 
House, The Quadrant, 
Sutton, Surrey SM2 5 AS. 





Sequencer 

Adrian Roe of Ilkley, whose Lightcycle 
game was published on page 164 of the 


BBC Bytes: Sequencer routine; VDU23 definition; Fill routine for 
graphics; Face — a computerised joke; Box spin 141 

Apple Pie: Disc patch program; Sub-exterminator game; HGR 
strings for graphics display 149 

Research Machines Review: Helicopter rescue game 154 
Newbrain: General-purpose graph; Format. 40 for column 
listings; Multiple screen display routines 156 

Sinclair Line-up: User-defined I/O routines; Smooth scroll 
routine; Side scroll routine; Bridge hand tuition; Correlation 
coefficient to help anyone using statistics 160 

End of File: Basic listing program for Sharp MZ-80B; High- 
resolution dump for Dragon 32; Nascom as terminal 164 



Guidelines for contributors 

Programs should be accompanied by 
documentation which explains to other 
readers what your program does and. if 
possible, how it does it. It helps if 
documentation is typed or printed with 
double-line spacing — cramped or 
handwritten material is liable to delay and 
error. 

Program listings should, if at all possible, be 
printed out. Use a new ribbon in your 


printer, please, so that we can print directly 
from a photograph of the listing and avoid 
typesetting errors. If all you can provide is a 
typed or handwritten listing, please make it 
clear and unambiguous; graphics 
characters, in particular, should be 
explained. 

PLEASE send a cassette or disc version 
of your program if at all possible. It will 
be returned after use. For CP/M 
programs use IBM-format 8in. floppy 
discs. 


May issue, has submitted a program which 
I cannot claim to understand for all my 
efforts to do so. The program, I am told, 
transforms my machine into a sequencer 
with key, octave, tempo and bass control 
over a basic note pattern input as data at 
line 220. 

Since the program uses the negative 
Inkey feature, interesting effects can be 
produced by holding down more than one 
key. Try holding the speed-up and pitch 
keys together, for example. 


Sequencer. 

10 REM***SEQENCER BY A. ROE JAN'83 

*** 

20 REM*******VERSION u.2********* 


30 M0DE2 

60 VDU23;tt202;U;0;U; 

50 PR0CINIT 
oO PK0CKEYS 
70 RESTORE 

8U READPIT : IFPIT=100U 60T070 
90 I FINKEY (-1 22) BASS=BASS+48 : S00 


ND2,2,BASS,1:SOUNDi,2,BASS,1 

100 I F INKEY (~26) BASS=BASS-48 : SOU 
N D2 , 2 ,B AS S , 1 :S0UND3,2,BASS,1 

110 I FINKEY (-54) KEY=KEY+4:BASS = BA 
SS+4 :S0UND2,2,BASS,1 : S0UND3 ,2 ,BASS , 1 
120 I F I NK E Y ( -5 1 ) KEY=KEY-4:BASS=8A 
SS-4: SOUND2,2,BASS,1 :S0UND3,2,BASS,1 
130 I FINKEY (-103) TEMP0=TEHP0+1 
140 IFINKEYC-104) TEMP0=TEMP0-1 
150 I F INKEY (-58) 0CT = 0CT + 48 
160 I F INKEY (-42 ) OCT=OCT-48 
1 70 S0UND0,-10,4,1 :S0UND1,1 ,PIT+0C 
T+KE Y , 1 

180 TIME S U : REPEAT UNTIL T IME>=TEMP 

0 

190 IFINKEY (-82)ANDPIT S 9 THENTIHE= 
0 : REPEAT UNTIL TIME>=200 :G0T0240 
200 G0T080 

210 REM***N0TE SEQUENCE** 

220 DATA9,37,49,57,49,37,29,37,1U0 

0 

230 REM***F INISH WITH 1000** 

240 MOD E7 
250 *F XI 5 ,0 

260 SOUND2,0,0,0:S0UND3, 0,0,0 

270 END 

280 DEFPR0CINIT 

290 VDU23,230,8,4,2,255,2,4,8,0 
30U VDU23, 23 1,16, 32, 64, 255, 64, 32,1 

(listing continued on next page) 


PRACTICAL COMPUTING October 1983 


141 




VDU23 definition 

Following on from Mr P Davidson's 
eight-by-eight pixel manipulation 
program — published on page 136 of the 
February issue — this implementation by 
John Wilson of Ben fleet, Essex provides 
far wider facilities. Up to 40 characters 
may be defined at a time on a cross-linked 
10-by-four set of eight-by-eight pixels. 

The resulting character definitions may 
be inverted from black to white and vice 
versa, Spooled for * Exec retrieval into a 
Basic source program, edited, and viewed 
in any mode. It is difficult to think of 
anything missing from the functions. 

Operating instructions are written into 
the program, with a function -select screen 


and subsequent prompts. The pixel map is 
represented as a grid of dots and an X 
cursor which is moved by the cursor- 
control keys. Pixels are selected with Copy 
and deleted with Delete. An agreeable 
feature is that the cursor controls can be 
held concurrently with select and deselect, 
providing rapid spreading or removal of 
lines in any of the eight cardinal 
directions. 

If you have OS 0.1 you will not be able 
to employ the full 10 by four generated 
character set in your own Basic programs 
as no provision is made within the OS to 
“explode 3 ' the memory allocation for 
user-defined characters. OS 1.0 and above 
does cater for this, as shown on pages 427 
and 428 of the User Guide under * FX20. 


VDU23 definition. 


1 0 

HEM 

5 70 

3 80 

E--1 

A=GET : I F A=15 AND E<>-1 THEN 

20 

REM Character Generator - V-I 

= E 


I 


590 

IF C=10 AND A=63 THEN VDU A, 8 

30 

REM 

■ E=1 0 ; 

GQT056U 

40 

REM for the BBC Micro Model B 

6 00 

IF A<49 OR A>48+C THEN 5aU 

50 

HEM 

610 

PRINT CHR$A; CHR88; 

60 

HEM by J.R* Wilson April 1983 

620 

E= A-48 

70 

HEM 

630 

GOTO 580 

80 

DIM MS 2560, T* 320, 1% 7 

6 40 

REM 

90 

XX=U;YX=0 

6 50 

REM Trap any errors 

100 

REM Make Cursor keys give cod 

660 

REM 

e s 


670 

IF E ft ft - 1 7 THEN 200 

110 

* F X4 , 1 

680 

REPORT 

120 

REM Trap any errors 

690 

IF ERR >200 THEN PROC SPA C£ (31 > 


(listing continued from previous page) 

6,0 

310 YDU23, 232, 16, 56, 84, 146, 16, 16,1 
6,0 

320 VDU 23, 233, 16, 16, 16, 146, 84, 56,1 
6,0 

330 EN VELOPE2 ,1 ,0,0,0,0,0,0,127,0, 
0,0,75,75 

340 ENVELQPE1, 1,0,0, 0,0, 0,0,127,-1 
0,-10, -1,126, 60 

350 0 CT-U iB AS S»9 : TEMP0=t6 :KE Y=0 
360 UDS-" - DOWN - UP " " 

370 ENDPROC 
380 DEFPROCKEYS 
390 C0L0UR1 

400 PRlNTTAB<3 ,1 ) "TEMPO CONTROL"!* 
EK1,4)"<";UDS;">":PR0CLINE(5) 

410 COLOUR?: FftINTTAB£2, 7) "SEQUENCE 
CONTROL"! ASM ,10>CHRS233UDSCHR$Z32 : 
PR0CLINE (1 1 ) 

420 C0LQUR3;PftINTTABU,13)"BA$5 CO 
NTRQL"T AS Cl , 1 61 CHRS231 U0SCHR423Q ;PR0 
CLINE (1 73 

430 COLOURS ;PRINTTAB(4, 19) "KEY CON 
TRQL"TABt1 ,22 ) "D"; UD$; "U PR0C LINE C2 
3) 

440 C GL0U R6 : P RINTTAB ( 4 ,2 5 ) "S TOP CO 
NTRGL"T AS C3 ,28 > "H OLD DOWN ' S 1 " 

450 ENDPROC 

460 DEFPROCLINECl) 

470 COLOUR?: FOHI=OTQ1 9 ; PR IPJTT AU 1 1 , 
D : NEXT 
48U ENDPRQC 


130 ON ERROR GOTO 670 

14U D=ti 

15U M=0 

1 60 XM-U : YF1=U 

170 REM 

1 HU REM Display menu 
190 REM 

2 UP MOD £4 
2 1 U VDU4 

220 NXI1EM-J&3UUII 

23U VDU 23,224,255,255,255,255,25 
6,255,255,255 

240 VDU23, 225, 0,0, 0,24, 24,0, 0,0 

250 C0L0UR1 29; CQLQURu 

260 PRINT STRINGS £240," ");TAB(U, 

o); 

270 PRINT '"CHARACTER 
GENERATOR 


: G 0 T 0 2 0 U 

700 PRINT " in Line ERL 
710 GOTO 770 
720 REM 

730 REM End the program 

740 REM 

750 DEF PROCEED 

760 VCJU22,7:KET1 Change to node 7 
770 P R I N T T A B ( O , 5 > 

7HU REN Give the cursor keys thei 
r usual function 
790 *FX4,U 
6UU END 
81 U R Eli 

820 HEM Enter a character into me 
mo r y 

83 U REM 

H 40 DEF PROC ENTER 


I 17U FUR 1%=U TO YMi 

II HO FUR J5t~0 TO XM 
1190 PRINT TAB(JX,I3£>; 

1200 IF 7 ( MX + J %+ 1 K * 80 ) -0 THEN VDU 
225 ELSE VDU 224 
1 210 NEXT J %,1% 

122U VDU 2 3 ; 8 20 2 ; 0 ; U ; U ; : R EM Make c 
u rso r invisible 

1230 IF X £ = 7 9 AND YX = 31 THEN VDU3, 
9,127 ELSE VDU4 
1 240 PRINT TABUX,Y3U;"X"; 

1 250 A8-GET8 

1260 PRINTTAB tXX, V4) ; 

1270 IF XX<>79 OR Y%<>31 THEN 1310 
1 28 U VDOV, 1 27,30 

1290 IF ?M* = 1 THEN VDU 224 ELSE VD 
0 225 

130U FRINTTAUCXX/YX); 


280 

FRlNTTAU M 5 ,4) ; 

">MENU< 

a 50 

PRINT 11 '"Number of characters 

1 31 U 

IF ? {n5S + XX + YX*80>=1 THEN VDO 

290 

C0L0UR1 

: COLOUR 1 28 

wide 

(1 to 9 or A ; where A =10 wid 

224 ELBE VDU 225 

300 

PRINT r 

" 1 

Enter characte 

e > M 

* 

1320 

REM Clear the keyboard buffer 

r“ 




860 

W=FNCH<10) 

133 0 

*FX 1 5 ,1 

310 

PRINT ' 

" 2 

Edit character 

67u 

PRINT' ' ' "N umber of characters 

1340 

REM Test the cursor keys 

IT 




deep 

Cl to 4) "; 

1350 

IF INKEYC-26) THEN X5£=ja-1 

3 20 

PRINT ' 

" 3 

Spool characte 

68U 

D = F N C H C4) 

1360 

IF INKEY t - 1 22) THEfJ XX-XX + 1 

r to i 

: a s s e 1 1 e " 



89U 

CL S 

1370 

IF INXEYC-42) THEN YX=YX+1 

530 

PRINT ' 

" 4 

View character 

VUO 

xn-w*8-i 

1 380 

IF INXEYC-58) THEN YX^YX-1 

" 




91 U 

YM=D*6"1 

1 39U 

REM Keep the cursor on the pi 

340 

PRINT 1 

" 5 

Invert charact 

9 20 

F 0 R I X =U T 0 Y M * 8LM- b U 

c t u re 


e r" 




93u 

t\% ? I x=u 

1 400 

IF Y X = -1 THEN Y Jii- YM 

350 

PRINT r 

" 6 

List codes" 

940 

NEXT 

1410 

IF Y X > Y H THEN YX^U 

3o0 

PRINT * 

" 7 

Operating s y s t 

950 

XX=0:YX=U 

1 420 

IF X^=-1 THEN XX=XM 

em call" 



960 

PHOCEDIT 

1 430 

IF XX>XM THEN X%-U 

37U 

PRINT f 

" 8 

Enel program" 

970 

ENDPROC 

1440 

REM Delete a block 

380 

PRINT 11 

‘"Press 

the number the 

9 80 

REM 

1 450 

IF 1 NKE Y ( -90) THEN ?C|U + X^ + Y% 

n RETURN 



99U 

HE IV Change the picture into b 

*80 ) =0 


39U 

A-FNCHC8) 


inary 


1460 

REM Leave a block 

4U0 

CIS 



1 UUU 

HEM 

1470 

IF INKEY < “1 Uo) THEN ?<|VX+XX+Y 

410 

IF A = 1 

THEN MODEL! sFROCENTEft 

1010 

DEf PRO C CHANGE 

X*80)= 

1 

4 20 

IF A = Z 

THEN MO DEO:H I MEM=8 3000 

1U2U 

PRINT '"Please wait a few sec 

1 480 

GOTO 1230 

: PROCEDIT 



ends. " 


' 1 d¥U 

HEN 

*30 

IF A =5 

THEN PHOCCHANGE IPHUCSP 

1 030 

FOR I*=0 TO D-1 

1 500 

REM What mode do you want to 


OOL 

440 IF A-4 THEN PHUC CHANGE : PRO C MO 
DEUtODE M i HIM £11 3 S3 000 : PROCVIEW 
45U IF A" 5 THEN PKOCINVEHT 
46U IF A" 8 THEN PJtOCEND 
47U IF A-6 THEN P ROC CHANGE ; PROC Li 


ST 


*8U IF A-7 THEN PHOCoscaU 
49U REM Clear keyboard buffer 
500 *FX 1 5 ,1 
510 GOTO 200 
520 REM 

530 REN Enter a number routine 
540 REN 
5 5U DEF f NCH CO 
560 LOCAL E , A 


1040 FOR JX=U TO H-1 
1 U50 FOR KX=0 TO 7 
1 ugU 7 CTX+KX+J X*ti+IX*80)=U 
1070 FOR LX=U TU 7 
1U8U H ? (MX + J X*8+L%+ t < IX*B+KX> *80 
))=1 THEN 7(T%+KX+J T 4*8 + U*80)=7tTK + K 
X + j5!*8+I%*8U)+2‘ t7-LW> 

1090 NEXT LSl,KSfi,J1£,I* 

1 10U ENDFRUC 
1110 REM . 

1120 REM Edit the picture 
1130 REM 

1140 DEF PHOCEDIT 

115U IF YM-U OR XM-U THEN ENDPROC 
1160 IF Y M=3 1 AND XM-79 THEN V D U 5 : 
REM Stop the screen from scrolling u 


display the character in ? 

1510 REM 

1520 DEFPHOChODE 

1530 PRINT TAUtU,lU);"What Mode fo 
r d i sp Lay 7 
1 540 I NPUT" "M 

1 5 50 IF IHU Oil M>6 OR IIOIMTN THEN 
CLS iGOTOl 53U 
156U ENDPROC 
1570 REM 

1580 REM Display the character 
1590 REM 

1600 DEF PHGCVIEW 
1610 FOR U = 0 TO D-1 
1620 FOR JX=U TO W“1 


142 


PRACTICAL COMPUTING October 7 983 


Open file: BBC 


163Q FOR LZ^U TO 7 
1 640 Z*?LS=? CTX+LX+JX*6+I4*8U) 

1650 NEXT L* 

1 66U 96023,224,?**, Z)t?1,ZX?2,Z*?3, 

Z)t 74 ,ZX? 5 / Z^? 6 ,ZltT 7 
1670 PRINT TA8(Ji( + 5,lK + 5>;CHIU224; 
1680 NEXT JK,I5t 

169U IF [4=3 OH H=6 THEN PRQCSPACEC 
24) : ENDPROC 

1700 IF M=2 OR N=3 THEN PROCSPACEl 
50) :EN0PRUC 


1710 

PROCSPACE (31 ) 

1720 

ENDPROC 

1750 

REM 

1740 

REM Press the BRACE BAR to co 

ntinue 

1750 

REM 

1760 

DEF PRQCSPACEm) 

1770 

F R I N T T AG ( 0 , Y X ) ; " P r e $ s the SPA 

CE OAR 

to continue."; 

1760 

REPEAT UNTIL GET**" 11 

1 790 

ENDPROC 

1 81)0 

REM 

1810 

REM Spool a character onto ta 

ssette 

1820 

REM 

183 0 

def pkocspqql 

1840 

INPUT TaB( 5 ,5 ) "F i r St characte 

r number = " 14 

1850 

I F N<5 2 OR N > 2 5 3 OR tiOINT (N ) 

THEN 

CLS : GOTO 1840 

1 801) 

INPUT TAb<5,1 U) "Fi rst Line nu 

tn b e r c 

" L 

1870 

IF L<U OR L > 3 2 7 6 7 OR L<>! NT < L 

) THEN 

1 86U 

I860 

*SPO'UL("CHAR 11 ) 

1890 

FOR IX-0 TO D-1 

1 900 

FUR J X=U TO W-1 

1 910 

PRINT ; L; " VDU 23, ";N; 

1 920 

FOR KX=U TO 7 

1 V30 

PRINT ?(TX+KX+JX*8+14*8U> 

"l94U 

NEXT K5S 

i960 

PRINT 

I960 

N = N + 1 

1970 

L-L + 1 1) 

1 V8U 

NEXT 

1 990 

*SPOUl 

200U 

PRUCSPACE (31 ) 

2U1G 

ENDPROC 

202 0 

REM 

2030 

REM Invert the picture in mem 

o ry . 

i.e. change all white blocks 

to black and vis a- versa 

2040 

REM 

2050 

DEF PROC INVERT 

2060 

PRINT 1 " P lease wait a few seco 

n d s . " 

2070 

FORIX=UTUYM*8U+80 

2080 

M% ?I%- (MX + 1 ) A N D 1 

2090 

NEXT IX 

2 1 00 

ENDPROC 

2 1 1 U 

REIl 

2120 

REM List the binary codes mak 

tng each character up 

2130 

REH 

2140 

DEF PHQCLIST 

2 1 51) 

FOR IX=U TO D-1 

2 1 dO 

FOR JX-U TO W-1 

2170 

CLS 

2 ISO 

PRINT "’Character at u ;JX+1j" 

, I X+1 

2190 

* H 1 i 

PRINT 11 "Codes are as follows 

2 2U0 

FOR KX=U TO 7 

2 210 

PRINT TAU(20);?(TX+KX+JX*6+IX 

*80) 

222U 

NEXTKX 

2 230 

PROCSPACE (31 ) 

2 240 

NEXT J % , X % 

2250 

ENDPROC 

2260 

REM 

2 270 

REM Allow you to make an 0.5. 

Call 

from within the program 

2280 

REN 

2 290 

DEF PROC os call 

2300 

PRINT TA&(U,5) ; "Type the requ 


i red operating system call and press 
RETURN, ,r 

2310 PRINT TAB<U,H)); M CaU = ,E ; 
232U INPUT ""CS 
2330 $6AUU=C3 
234U XX=U:YX-6A 
2350 PHIMTTAS (U,15> ; 

7360 CALL&FFF7 
7370 ENDPROC 


A Fill routine, 

6 HEM The variables in the testb 
ed are: cursor at x , y ; v ” 4 for c u r s o 
r moving, 5 for cursor drawing; use 
cursor control keys and joystick if 
available else REM out line 130 and 
remove the OR ( (ADVAL (U ) AND3 ) <>U > fro 
m line 7U 

10 OAT A RED, G REE N,YE L LOW , ALOE, MAG 
ENT A, CYAN, WHITE 

70 MODE? : PRINT 4 1 1 1 ' "The colour co 
des used a r t : H 1 ' : F ORI -1 T07 : READ c o l * : 
printchr$(128+i>;" ,l ;i; H for co 

IS;SPCC10-LEHCcoL*>>;CHR# 157;CHR*C1Z 
8 + 1) : NEXT ; PH INI * M, and U for black”' ' 

,r press space to go on PRO C gk ( 11 > 
30 MO DE3:PRINT" Controls are:"""* 

B or F change the background or fore 

ground to the number keyed after C 

clears to MODE number keyed after" 1 
"SPACE or Trigger toggles between MO 
V E and 0 RA W" r " A r r □ w$ and joystick wo 
rk" * "COPY fills' 1 

4u PRINT "k sets a border G goes 

to it ,t1M 0 sets an or i ent a t i on" 1 ,r N a 
number of sides 1M "H draws a polygon 

M "*T writes text 'til RETURN A var 

i es the GCGL option 0 plot 1 UR 7 AN 
D 3 EUK 4 Invert" 1 ’"press space to g 

0 on, , , 

5U PROCgkC" "))x=5Ui);y-5UU:edgex-L 
x ; edgey=y ; rad = U : v=4; gtype=0 : or 1 ent=U 
: si des -36; for e%-7sbackX=0: MODE 7:M0V 
Ex,y:VDU5:FRQCcaf f : REP EAT t * F XI 5 ,G 
OU IF INKEY (-68) TH ENf o reX=V AL ( GETS 
) :GCQLgtype,foreXEL$EIF INKEY (-101 >TK 
ENbackX=VALlGET£) :GCOLgtype, PeCkX + U 
8 ELSE! F INKEY < -83 JTHENFROCg k ("01 7") : 
MODE VAL(aS)i NOVEK,y :VDUS :PH0Ccof f s(i 
C0Lgtype,foreX:GCQLgtype,128+backX 
7 U tog^INKEY (-99 ) 0 H < ( AD V AL ( U ) AND3 
) <>U>: IF tog AND v = 4TH ENv^S : P80C de l ay ( 
10)EL5EiFtog AND V=5THEN v = 4 : P ROCde l ay 
110) EL SEIF INKEY (-36 ) I KENPRO C de L ay (25 
) : PRO C text ELSE IF INKEY C-6&) T KENFROCg 
k("U173 4 ,< ); y t yp e=V AL C a* > 1 G COLg type , f 
ureSfiGCOLgtype/l^a + backX 

60 IF INKEY t-52)THENedyex*x;edgey* 
y : rad*U ELSEI FINKEY <-84>THENx“edyex 1 
y = e dgey ; MUV E x , y ELS El F INKEY (-5 5 ) THEN 
PRGCorlent ELSEIFINKQY (-66 ) T H ENP ROC s 
ides ELSE! FINKEY (-107) THENPROCpolygon 
9U IFlNKEYl-56)THENPROCP(U,4) 

100 I F INKEY("42 ) THENPROC P £0,-4) 

110 I FINKEY (-76) THENPROC P (-4,0) 

1 70 I FINKEY(-122)THENFR0CP(4,U) 

130 PHOCP(FNad£AUVAL(2>) / FMad(ADVA 
L (1 ) > > : R EM this line out if you don 1 
t want joystick control 

1 40 PROC ciPROCc : I FINKEY 1-1 06>TH.EJ1P 
ROC FILL (x,y,oackx) : HGVEx,y: 9»4 

150 UNTIL FALSE 

160 DEFFNad(AX) : I F AX<25U0UTHEN=I NT 
( UW5UUU) /1U0U) ELSE I F AX> 400UUTH EN 
= INK (AX-40UUU) /100u) ELSE=U 

170 DEFPROCc:PLOT7,12,17:PLOT7,”74 
,U:PLOT7,U,-74:PU>T2,24,U:PLOT2,U,74 
; PL0T2,- 12 ,-12 ; ENDPROC 

180 DEFPROCpolygon : I F rad-UTMEN rad- 
F N h y p e 

190 startK=x+CUS(orient)*rad: start 
y »y + SIN (orient)*rad:MOVEstartx, start 
y : FORang le=or i ent TOor i e nt+ 2 *P I STEP 
2*PI/sides:newx=x+CD$(angle)*rad;ne 
w y = y + S I N ( a n© L e ) * r a d ; D R A U n e w x , n e w y i N E 
XT:IFnewx<>startx ORnewy <>s tarty THE 
NDHMJstartx,starty 
700 M0VEx,y:£NDPR0C 
2 10 DEFPROCPCXI,YI) ; I F x+XI <t 280 AND 

x + X I > U TH E N x = x +X x 

2 70 I F y+ Y I< 1 U2 4ANDy + Y 1 PUT HEMy-y + Y I 
230 PLOT v,x,y;ENDPROC 

2 4U 0 E FPROCcoff: PROCosoyte (697 ,U , 1 
U ) : PRO Cosby te (£97,1 ,32) : ENDPROC 

2 50 D EF PRO C con: PRO COS byte (697,0, 1U 
>:PROCosbyte (697,1 ,9d > i END PR0C 

26U DEFPROCosby te (AX,XX,YX) ; i nd^OS 
R (6FFF4) : ENDPROC 

270 DEFPROCgk (lega IS ) : R E PEAT a$ = G £ T 

1 :IFa8>= ,t A"ANOai< = "Z 1, THENa8"CHR$<ASC 
(a*)+32) 

260 P-R'OCck: UNTIL Lega L : END PRO C 
2 90 DEFPROCCk: lega 1= FALSE: ind=U:RE 
PEAT i nd*H nd+1 ; I F MI D$ (1 ega 18, i nd,l) 

= a* THEN Lega l-TRUE 

300 UNTIL legal OR ind=LENUeya 15) 

: ENDPROC 


A Fill routine 

Douglas Stewart of Edinburgh has 
submitted another recursive procedure 
demonstrating that not all recursion is 
superfluous extravagance coded for effect 
rather than utility. This routine will fill an 
area of background colour bounded by 
non-background colour with foreground 
colour. 

Within this bald description lies a 
process which is a joy to watch on the 
screen, as colour first flows up, then 
down, filling nooks and crannies of 
irregular shapes, and back-tracking to 
finish off part-completed sections. The 
Fill function is essential to any graphics art 
pack, and the test bed in which the 
procedure is set will allow pictures to be 
drawn. It provides a good grounding from 
which you can develop an art pack tailored 
to your own specification. The routine can 
be included within any program requiring 
a Fill facility; the testbed is optional, 

310 DEFPRUCdelay (AX) :TX”TIhE:REPEA 
T UNTIL TIME>U + AX:ENBPRQC 

321) DEFPRUCorient:orient = ASNC Cy-ed 
gey) / ( F N hy pe+U , 001 ) ) : I F x-odgex<UTH EN 
orient=orient+Pl 
330 ENDPROC 

3 4U DGFPROCsi Oes sPRUCgk <"34567iJ9ab 
cdefghijk Imopqrstuvwxyz"): 5ides = ASC( 
a fe ) : I F s i d e s > 9 6 T HEN side s= sides- 86 ELSE 
% i des”S ides-48 
55U ENDPHOC 

3 00 DEFFNhypet=saK(<x“edgex)*2+(y- 
odgey ) *2) 

3 70 0 E FPRQ C text: REPEAT : a6=GETS : PR I 
NTai; ;UNTILaS=CHRS13 iENDPRUC 
30000 REM Procedure to fill an area 
of current backgroud colour which is 
3Q010 REM enclosed by non-background 
colour, 

3UU2U REM Syntax Is PKU C F I LL (Xc oordi 
n a t e , Y c o □ r d i n a t e , c u r r e n t_b a c k g r o u nd_ 
colour) 

3UU3U REM Procedure will work in any 
mode, 

30040 HEM Oy Douglas Stewart, March 
1983. 

3 1)050 REM ************ NOTE ; OPERA 
TINE SYSTEM SERIES 1 OR LATER ONLY * 
* ** ** 

30060 K EM 


30070 REM As the function is recursi 
ve for more complex shapes, short var 
i ab L e 

3UU8U REM names have been used to Li 
mit the stack space used. 

30090 DE FPROCFILL (X ,Y,V > 

301 UD DIM PAR AM 7: REM Space for para 
meter block for OSHOHD 13, 

8U11U V=V AND15 
3U120 LUC ALM 

3U13U AX = 135:M=CCUSR CiF F F4 ) D I V6 1 0000 
) ANDl 5 > -1 : R EM Current graphics mode. 
3U140 I F H- 7 ORM" 3 0 RM- 6 EM D PR 0 C : REM Che 
ck for non-graphics mode, 

3 015 0 W-2KM HOD3 + 1 ) ; HEM Width of pi 
xel for this mode. 

301 60 1-2 *W 

3U17U PR0CUD(X,Y,4):PRQCUDCX,Y,-4):R 

EM FILL UP AND DOWN 

30180 ENDPHOC 

30190 DEFPROCUD <X,Y,S> 

30200 LOCALFX,BX, CX,DX, EX :ft£M These 
variables must be LOCAL 
30210 PLOT76,X,Y:RE M Bet width but d 
o not draw yet. 

3 02 20 8X-F N C (4 ) ; RE[i Bet last X coord 
inate. 

30230 CX = FNC (0 > ; HEM Get previous X' c 
oordi n ate. 

3 024U : 

30250 REM ******* Main Loop starts h 
ere. ******* 

3U26U PL0T77 ,X , Y : REH Fill a horiz 
ontal line. 

(continued on page 147) 


PRACTICAL COMPUTING October 1983 


143 



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PRACTICAL COMPUTING October 1983 


144 





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PRACTICAL COMPUTING October 1983 


• Circle No, 184 

145 





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Open file: BBC 


Face 

Alistair Lindsay of Edinburgh has 
submitted what he calls his first successful 
attempt at making a reasonable program. 
The result is a Mode 7 graphic display — 
not the easiest problem to start on! — 
which does just what it sets out to do; it is 
quite funny* 

I can see a whole set of computer jokes 
resulting from it — variations on the 
“Mummy, Mummy” or “Knock, Knock” 
themes of yesteryear — but this is the first. 
Nobody has submitted a computerised joke 
before. Given enough of them chained 
together, it might be the music-hall turn 
reborn. 

Box spin 

R A Lober of Peterson-super-Ely, 
Cardiff, has submitted a demonstration of 
graphics rotation. I had not previously 
thought it possible in Basic but Mr Lober 
proves me wrong — though 1 suspect that 
is only because the box he is spinning is 
rather small and only four of its faces are 
ever visible. The following variables are 
used: 

A% — width of sides 
B% — width of ends 
1% — angle of turn 
D — current width of sides 
P — current width of ends 
S — perspective 
W — reduction in D 
F — reduction in P 
(tisiing continued from page 143} 

3U2?U Y = Y+S 
3U28U k>% = FN£U) 

30290 E*=FNC(U) 

3U3UU IFEWX<Z THEWS tii5U ; HEM Extrero 
i t i e $ almost coincident! 

S03 1 0 FX-CX 
3U3ZU FX=FZ+W 

30330 IFPOINT(FK,Y-S>=V PROCUD l FTC, Y- 

S , S ) : fl € ti Recurse to FILL branch 

3U34U IF FX<£XTHEN3U32U 

3U35U I F EJ% -U-5L <Z THEH3U4U0 

3U36U FX = DH 

5U370 FJt = FJt + W 

3U38U I F POI NT C F Jt JP Y-S) =V PROCUD ( FX , Y- 

5 { kEM Recur se to FILL branch* 

503 VO I F FX<BK YHEN303 70 

:>U4t)0 IFC4-EJKZ THEN3U430 
'30410 ¥% = EX 
3Q420 F£=F*+W 

3 0430 IFP0INT(fX,Y-2*S)=V FR0CU0CF*, 
Y“2*S,“S > : R EM Re curse to FILL branch 
3U44Q IFFX4CXTHEN3U420 
3U45U IFD5fi-BX<Z T KEN3U50U 
30460 FX=B£ 

30470 FX=FX+U 

30480 I FP'G'XNT t FX, Y“2 *S 5 =V PROCUfKFX, 
Y-2*S ,-S> ; REM fiecurse to FILL branch 
3 0490 I F F%<D3 pTHEN3G47U 
3 05U0 = 

30510 C% = E% 

30520 IFPQINT(X,Y)<>V THEN30530ELSE3 
J260 

50530 l FP01HT (X / Y>=-1 ENDPR0C ; IE If i 
t Is off the edge of screen* 

3 0540 FX = EX 
30550 REPEAT 
30560 F4-F&+W 

50570 UNTILF*>0%OfiPQIHT<F*,Y)=V 

30580 I FFX>DXEN(JPR0C 

30590 X = FX 

30600 GOT030260 

30610 : 

30640 R EM THIS FUNCTION OSES QSWORD 
13 TO GET THE LAST POINTS VISITED 
30630 RErt VARIABLE 0 IS THE OFFSET 0 
F THE AREA TO BE REAP IN THE PARAH. 
BLOCK . 

30640 DEFFNCtO) ; AX-15 : XX^PAftAM MOD25 

6 : YX=P AR Afl D I V 2 5 O': C'AL Lfi f F F 1 ;«(PARA3U 
0) ANDkf FFF 


Face. 


1 0 MODE? 

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57 b CHR?{ 135 b " WELCOME TO T11B BBC MIC 
RQ COMPUTER" 

30 PRINT CUR? (141 ) ; CHR? (129) ;CHR?(l 
57) ; CUR? t 135] r " WELCOME TO THE 3 R C MIC 
RO COMPUTER" 

40 PRINT CHK${14lhCliR$(129'bCHR$(l 
57);CHR$(i35b "1 AM GOING TO DEMGNSTRAI 
T WHAT I" 

50 PRINT ‘CUR? (141): CUR? (129); CUR? ( 1 
5 7 ) : CHR? ( 1 35 ) } " I AM GOING TO DEMONSTRAI 
T WHAT I" 

60 PRINT CHKSU41) ;CHR${129) f CHR?(l 
57) ; CHR? (135); " CAN DO' 1 

70 PRINT CHR?( 141bCHR?U29bCHE5{l 
57) ; CHR? (1351 t" CAN DO" 

B0 PRINTt PRINT: PRINT; PRINT: PRINT CH 
ft? (133);" PRESS' Y' TO GO ON OR 1 N * TO GO 
BACK" 

90 A? -GET ? 

lOO IF A?- "N" THEN GOTOIQ 

104 IF A?= h Y“ THEN GGTOllO 

105 GQTO90 
110 CLS 

1 20 NODE2 

110 90021, 86, 255, 255,255,255, 255, 255 

, 255 , 255 : VDU23,81 , 254 , 254, 254,126,62,30 
, 14 p 6, 23,90,255, 255, 255,255, 0,0, 0,0 
140 COLON R3 : PR I NT " XX XXXX 11 

150 COLOU R3 ! PRINT 1 * XXX X XXXX " 

1 60 COLOU R 3 ; P R I NT " X XXXXXX XXX " 

1 70 COLOUR! i PRINT" XX " ; : COLOURS : P 

R I NT"XXXXXXXX" ; ; CO LOUR 3 ; PRINT" XX" 

1 m COLOUR! s PRINT" X " ; ; COLOURS; PR 

I NT " XX XXX XX XXX : COLOURS : P R I NT " X " 

190 COLOURS: PRINT 4 ' XXXXXXXXXXXXXX" 

200 COLOURS; PRINT" XXX " ; : CQLQUR7 ; PR 
I NT 14 XXX" ; ; COLOURS: PRINT" X" ; ; COLOUR! : PRI 
NT" XX"; : COLOURS : PRINT" X" , : COLOUR? : PRINT 
"XXX" ; : COLOURS ; PRlNT”XXX' h 

210 COLOURS: PRINT" XXX H ; : COLOUR? : p R 
I NT 14 XX " ■ : COLOUR*! ; PRINT " X" j : COLOU RS : PRI N 
X h ; ; CUL0UR4 ; PRINT - X " ; i COLOUR? : PRI NT" XX" 
f l COLOURS; PRINT "XXX" 

2 20 COIjOURS; PRINT" XXXXXXX" ; :CQL0UR 
1 s PRINT" XX" ; ; COLOURS ; PRINT" XX XX XXX " 

230 COLOURS : PRINT " XXXXXXX " ; : COLOUR 
1 : PRINT" XX" ; : CGLOUR5 : PR I NT " XXXXXXX 14 

2 40 COLOURS : PRINT " XXXXX" ; : COLOURl 
: PRI NT" XXXX" ; : COLOURS ; PR I NT" XXXXX" 

250 COLOURS: PRINT" XXXXX" 7 : COLOURl 
: PRINT" XXXX" ; : COLOURS : PRINT "XXXXX" 

260 COLOURS : PRINT" XXXXXXXXXXXX 1 
270 COLOURS : PRINT" XXXXXXXXXX" 

2 SO COLOURS : PRINT" XX" ; ; COLOUR! : 

PRI NT" XXXXXX" ; : COLOURS : PRI NT" XX" 

290 COLOURS : PRINT" X " f : COLOURl : 

PRINT"*" ; iCOLOURO : PRINT M X" : : COLOUR? : PRI 
NT"gi5"; :COLOUR0: PRINT" X 14 ; : COLOURl s PRINT 
“X"; : COLOURS : PRINT’VX " 

300 COLOURS: PRINT" X " ‘ : COLOURl : 

PRINT" XXXXXX 1 ’ ; ; COLOU R5 : PRINT " X " 

310 COLOURS: PRINT" XXXXXXXX" 

320 COLOURS: PRINT" XXXXXX" 

330 P R I NT ; PR I NT " I'VE GONE BANANAS" 
340 FOR 1=1 TO 3 

350 COLOUR? ; PRI NTTAB ( S , 6 ) 7 " XX r4 ; ; COL 
OUR4 :PRINT"X" , ; COLOUR? ; PKINTTAB( 5,7): "X 
XX" :COLOUR4 : PRINTTABt 12,6) ;-"X"; : COLOUR? 
: PRINT " XX COLOU r 7;PRINTTAB( 12,7) ; 4 XXX" 
360 FOR J=1 TO 300: NEXT J 
370 COLOUR? : PRINTTABt 5 f 6) ; "X"? :COLO 
U R4 ; PRINT" X " ; ; COLOUR? : PRI NT" X " : : COLOUR? 
: PRINTTABt S , 7 ) - "XXX" ; COLOUR? : FRlHTTAB ( 1 
2 , 6 ) : " X " ; : CGLQLJR4 ; PRINT" X " ; : COLOU R7 ; PRI 
N T “ X " : COLOUR? ; PHI NTT All (12,71; "XXX" 

300 FOR J«l TO 300 t NEXT J 
390 COLOU R4 : Pill NTTAB ( S , 6 ) ; " X u ; ; COLO U 
R7 ; PRI NT" XX" : COLOUR? 1 PRlNTTAB( 5 , 7 1 ; "XXX 
" ; COLOUR? : PRI NTTAB ( 1 2 , 6 b " XX " ; : COLOU R4 : 
PRINT"X 14 : COLOUR? : PRINTTAJlt 12,7 b "XXX 11 
400 FOR J^L TO 3Q0;NEXTJ 
410 COLOUR?: PRI NTTAB (5 ,6 ) ; "XXX" ;COLO 
U R4 : PR I NTTAB ( 5 , 7 1 ; "X " ; : COLOUR? : PRINT "XX 
" 8 COLOUR7 : PRINTTAtl( L2, 6 j; 14 XXX" : COLGLJR7 : 
PRlNTTAElt 12,7); "XX" ; : COLOU R4: PRI NT" X" 

4 20 FOR TO 3 00 : N EXT J 
4 30 COLOUR? : PRI NTTAB ( S , 6 ) ; "XXX" :COL0 
UK? : PRI NTTAB ( S , 7 ) ; "X"; : CQLOUR4 : PRINT" X 41 
; ; COLOUR? : PliINT ,, X " : COLOUR? : P!il NTTA b( 1 2 , 
6 } ; "XXX" : COLOUR? : PRI NTTAB ( 12, 7 } b'X"; ; CO 
LOUH4 : PRINT "X" ; : COLOUR? : PRINT"*" 

440 FOR J=1 TO 300 : NEXTJ 
450 COLOUR7 : PRINTTABt 5,6); "XXX" : COLO 
UR7 : PRI NTTAB ( 5,7); "XX" ; : COLOUR4 : PR 1NT " X 
" : COIjOUR? : PRI NTTAB (12,6); "XXX" : COLOUR4 : 
PRINTTABt 12,7); "X"; : COLOUFi? : PEIINT"XX" 

460 VDU3 1,0,0 

461 NEXT I 

4 70 FOR '4=0 TO 255 
4SO MkDl,-I5,Z, 1 

490 WEXT4 

491 FORY=lS5 TO 0 ST E P-1 

492 SQUND1 , - 1 5 , Y , 1 


493 NEXTY 

SLO CS-INKEV? (10) 

520 MODE 7 

530 PHINTCHR? (141 );CUR5(136l;CHR?(13 
4);" HOW DID YOU LIKE THAT? IF YOU " 
S40 PRINTCHR? (141 1 ; CHRS ( 1 36 ) ; CHR? (13 
4b" HOW DID YOU LIKE THAT? IF YOU " 
550 P;|lNTCUK5U41 ) ; CHR? ( 1 36 1 ;CHR?U3 
4); "DID PRESS’ V IF NOT PRESS* ft f " 

560 PRINTCHRS(l4U?CKESU36bCHR$U3 
4);" DID PRESS' Y ' IF NOT PRESS 
590 D? 3 GET? 

600 IF D?= "Y " THEN GOTO630 
610 IF D?= U N" THEN GOTO 620 
615 GOTO 600 

620 PRINTCHR? (135); CHR? (157); CHR? ( i 2 
9b" YOU'VE HURT MY FEELINGS" 

625 G$-IftKEY? (1000) 

626 GOTO 10 

630 CLS : PRlftTCUR? ( 141 )’; CHR? (136) ; CHR 
$ (133 ) ; CHR? (157 1 ;CHR5(13t ) 7 "THANK YOU F 
OR RRAISEING MY ART FAN" 

640 PRINT CHR$ (141 ) ; CHR? ( 136 bCHK? (13 
3 ) ; CHR? (15?); CHR? ( 1 31 ) ; "THANK YOU FOR P 
RAISE IMG MY ART FAN" 

6S0 PRI NTCUR? (141); CHR$ (136); CUR? ( 1 
33 ) ;CHK? (I 5? ) ;CUR? (131);" THATS 

ALL FOLKS" 

660 PRI NTC HR? (141 ) ; CHR? < 1 36 ) ; CHR? (1 

3 3 ) ;;CHR? (157b CHR? (131);" THATS 

ALL FOLKS" 


Box 

spin* 


1 

AX=0 


10 

REM BOX SPIN 


20 

REM U> Copyright R-A-Lober 


30 

REM 2.3,83 


31 

Atf-AX+1 ; I FA!fi<3 G0T010 


40 

MGDEQ 


50 

as:=ioo 


60 

B% = 50 


70 

0 = 50 


60 

VE>U29,640;512; 


90 

TIME-O 


100 

F0RT%=0T0360STEP10 


110 

D=AX*C0S CR AD (TX) ) 


1 20 

P=B%*S IN (RAD (TX) ) 


130 

S = 2 *P/ 3 


140 

W=ABSCSM> 


150 

F = D / 2 5 


1 60 

GCOLO 1 1 :MOVE128 / 70:DRAW128 < , 

ISO 

170 

GC0L4,1 


iao 

FORC^-OTOI 


190 

I FP<OGOTOZ 1 0 


200 

PROCENDA 


211) 

IFD-W<W“t> G0T0230 


2 20 

PROCSIDEA 


221 

FQRDE=1T050:NEXT 


230 

IFP>UG0T0250 


2 40 

PROCENOa 


250 

IfD + H>-<D + H> G0T0270 


2 60 

procsideb 


270 

■ 


280 

NEXT :HEXT 


2 90 

RUN 


3 00 

DEFPROCSIOEA 


310 

K0VE1 ZS+D-P-W^I 50+S+F 


320 

DRAW128-D-P+W a 150-S+F 


330 

DRAW1 28-D-P+W / 1 00+S-F 


3 40 

DRAW1 28+D-P-W,1 DU-S-F 


350 

DRAW1 Z8+D“F“W,1 50+S+F 


3 60 

I FC%=QFQRN=QTOGrNEXT 


370 

ENOPROC 


380 

9 E FPROCENOA 


390 

MQVElZa+D-P-W,1 00-S-F 


400 

ORAW12S+D+PFW,100-S+F 


410 

D R. A W1 2S + D+P+W ^150 + S-F 


420 

DRAW128+D-P-W,150+S+F 


430 

DRAWl28+b“P-W,i 00-S-F 


440 

IFC%=0FORN=O TOO; NEXT 


450 

EN D PRO C 


460 

DEFPROCSIDEB 


4 70 

M0VE1 aa-D'f-P-W^I 00 + S + F 


480 

DRAW1 28+D+P+W^IOO-S+F 


4 9U 

DRAU1 28+D+P+W^I SO+S-F 


5 00 

DRAW1 28-D^P-W,1 SO-S-F 


510 

DR AMI 28-D+P-U,1UU+$+F 


52Q 

I FCX =0 F 0 RN=0T00 : NE XT 


530 

ENOPROC 


540 

DEFPROCENDB 


550 

MOVEl28-D+P-W,lDO+$fF 


560 

0RAW128-D-P+W,1D0+S"F 


570 

DRAW1 28-C-P+W,1 50-S+F 


580 

DRAW1 28-D+P-W,1 50-S-F 


590 

DRAW128-D+P-U,100+S+F 


600 

I FCX = OFORN = CiOO;NEXT 

0 

61 0 

ENDPROC 


PRACTICAL COMPUTING October 1983 


147 



LONDON COMPUTER CENTRE 


8/16 bit SOFTWARE 

The comprehensive range includes 


WORDSTAR £235 


DBASE II £325 


SUPERCALC £170 


SPELLING CHECKER £80 

WORD PROCESSING 

£ 

LANGUAGES 

£ 

SpellBinder 

Magic Wand 

290 

MBasic 

210 

226 

M Basic Compiler 

230 

Spellstar 

134 

Fortran 80/86 

325 

Mailmerge 

134 

Cis Cobol/Forms2 

399/105 

Grammatik 

85 

Pascal M 

250 

FINANCIAL PLANNING 

Pascal MTi/SSP 

350 

Calcstar 

85 

ACCOUNTING 


Multiplan 

170 

Pegasus from 

250 

Plannercalc 

75 

Peachtree from 

325 

T/Maker 111 

175 

Tabs from 

199 

Microplan 

DBASE CORNER 

200 

Exact 

500 


Pulsar from 

195 

Autocode 

195 

COMMUNICATIONS 

Quickcode 

205 

Bstam 

130 

D Base Window 

150 

Crosstalk 

135 

UTILITIES 

Sid £60, ZSid £76, Mac £133 

Moveit 80/86 

90/105 

FORMATS: Superbrain, Televideo, Sirius. Sanyo, Osborne 


Northstar, 8" SD, DEC. Epson QX-10. IBM 
ICL,H-P, XEROX, ALTOS. ' 

All prices are exclusive of VAT 


SPECIAL OFFER £99 

GRAMMATIK 

One of the most useful tools you can use with your word 
processor which improves your writing style and corrects 
your grammar. 

PROOFREADER (Spelling Checker) 

Avery powerful and easy to use spelling checker with a 
standard dictionary of 30000 words and facilities to 
create your own dictionaries. It checks your errors in 
seconds, displays possible corrections and then updates 
the text automatically. 

Grammatik and Proofreader have been designed to 
work together to provide the state of art in computerized 
document reading. 

Normally priced at £85 and £80 respectively, but now in 
a SPECIAL OFFER at £99 for the two until the end of 
October. 


It's compatible with Wordstar, Spellbinder, Peachtext, 
Magic Wand & Other CP/M based Word Processors 
and available on the formats listed, 


43 Grafton Way, London W1 P 5LA (Opposite Maples) 
Opening Hours: 10-7 Mon-Fri. 12-4 Sat. 

01-387 4455 (4 lines) Telephone Answering Service After Office Hours 

Telex: 8953742 


' Circle No. 157 



MAILING 
FLOPPY DISKS? 


The Swan Disc Pack combines great strength 
with simplicity of use. Made from rigid white 
corrugated, it is a self assembly package 
providing high postal security ai 
economical rates. 


Free sample 
ring us on 
01-607 9938 



Alsu, xpeeial ofltrs including dun covers (rot computer, monitor, printer, 

disks), cassette leads and 3.2 ROMS FOR ONLY £*.50 INCLUSIVE - DIE CHEAPEST I’RICIE ANYYCH IFRti! 
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defici deserijstiPh - s^nd off for a sample eopt and yuull find ihaL H sells it self HQ you. See one 
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Fkase supply me with | ] more details about 




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J ] a sample copy for £L(K) and ati A4 SAE (17p postage) 

| ] t UK 12 Month Subscription Tor £12,00 

( ] I UK 6 Month Subscription for £6.00 

[ ] t Overseas Surface Mail Subscription for £14.00 

(air mail rates on application) 


F lease send the goods to: 
NAME 


I enclose a chrqur/PO for £ p made payable w I.ASEREUG. 


Please send the form lO LA5ERBUG Dept. P. 10 Da win v Rade, Colnbrook, Slouch, 0erks>, SE.3 0QM. 

• Circle No. 188 


PRACTICAL COMPUTING October 1983 


148 






Open file: Apple 1 


APPLE 

PIE 

by John Harris 



Patch 

an excellent 16-sector disc-patch 
program or catalogue analyser is 
submitted by Mark Benson of Tring. Any 
sector of a regularly formatted Apple 
floppy — which excludes tiresome 
commercially screwed discs like V is i Calc 
— may be read, amended* written or 
rewritten, with comprehensive prompts at 
the appropriate point. 

While it ovides a perfect way of 
learning about catalogue and program 
layout If the Write options are avoided, it is 
a guaranteed way of losing disc data if you 
do not know what you are about. Given 
that you do, Mark Benson has written an 
excellent utility to do it with. 

The associated assembler routine — for 
which 1 have no source code — is to be 
saved as; 

BSAVE B PATCH ,A&0295 r L$01 13 
For use on 13-sector discs the following 
amendments are needed; 

Line 140. *16 becomes *13 
Line 670. <16 becomes <13 
Line 710. =15 becomes =12 
Line 1050. =15 becomes =12 


Patch. 








*0295. 03H7 







0295- A5 

3C 

29 






029Q- FS 

85 

3C 

38 

A5 

3E 

E5 

3C 

02A0- AS 

3F 

E5 

3D 

80 

Ol 

60 

AS 

02AS- 3C 

20 

DA 

FD 

A2 

02 

20 

4A 

0280“ F9 

AO 

OO 

81 

3C 

20 

DA 

FO 

02BS- A2 

01 

20 

4A 

F9 

C8 

CO 

08 

Q2C0- DO 

Fi 

FO 

02 

OO 

00 

A2 

01 

02CQ- 20 

4A 

F9 

AO 

00 

B1 

3C 

09 

0200- 80 

C9 

AO 

BO 

04 

A9 

AO 

80 

02DB- 06 

C9 

80 

90 

02 

E9 

20 

20 

02E0- ED 

FD 

CO 

CO 

00 

DO 

E6 

A9 

02E8- 8D 

20 

ED 

FD 

18 

AS 

3C 

05 

G2FO- 40 

69 

08 

85 

3C 

AS 

3D 

85 

02FS- 41 

69 

00 

85 

3D 

90 

9C 

60 

0300- IB 

90 

68 

A9 

04 

DO 

27 

A5 

0308- IF 

4C 

DA 

FD 

A9 

Ol 

DO 

02 

0310- A9 

02 

48 

20 

E3 

03 

85 

49 

0318- 84 

4B 

AO 

OC 

68 

91 

48 

20 

0320- E3 

03 

20 

D9 

03 

BO 

06 

A9 

0328- GO 

AO 

OD 

91 

48 

60 

48 

20 

0330- E3 

03 

84 

48 

85 

49 

AO 

04 

0338- 81 

48 

85 

IE 

CB 

El 

48 

65 

0340- IF 

68 

85 

49 

A9 

24 

85 

48 

0348- A2 

02 

AO 

03 

18 

as 

ID 

29 

0350- OF 

08 

IB 

69 

80 

C9 

BA 

90 

0358“ 02 

69 

06 

91 

48 

88 

29 

80 

0360- 09 

85 

ID 

4ft 

4A 

4A 

4A 

38 

0368- 80 

E7 

CA 

DO 

DF 

60 

20 

E3 

0370- 03 

ac 

CO 

03 

BD 

Cl 

03 

A9 

0378- 86 

85 

4B 

AD 

E5 

03 

85 

49 

0380- AO 

00 

81 

40 

DO 

OD 

A5 

CC 

O3B0- 8D 

C2 

03 

AS 

CD 

A6 

CA 

A4 

0390- CS 

90 

08 

AS 

6D 

OD 

C2 

03 

0398“ AS 

6E 

A6 

6F 

A4 

70 

BD 

C3 

03 AO- 03 

88 

C4 

03 

ac 

CS 

03 

60 


Patch. 

800 

POKE 36,0: POKE 37,6: CALL - 
990 

POKE 35,22: CALL - 936 



810 

10 

IF GO THEN 170 

820 

POKE 35,24 

20 

BO - 1 

830 

PRINT “■ OPTIONS AVAILABLE 

30 KB = - 16304 : KS “ - 16360:MD 


PRINT 


= 661 

040 

POKE 32,5: POKE 33, 35: CALL 

40 

TEX T : CALL - 936 


- 990 

50 

PAINT CHA* t4M 'BLOAD BpATCH 

850 

PRINT 'T DISPLAY BYTES 00-7 

F . Hl 

60 

PRINT ”16 SECTOR DISC PATCH : 

860 

PRINT "8 DISPLAY BYTES 80“ F 

F . 11 ; PRINT 

70 

PRINT 

070 

PRINT "R RE-READ CURRENT SE 

00 

FDKE 34, 3 


CTOR. H 

90 

GDSUB 1450 

800 

PRINT ”W WRITE BACK CURRENT 

100 

6 = PEEK (LP + 1) + 2 


SECTOR, " : PRINT 

1 10 

BB =* B * 128: BB - BB + BB 

890 

PRINT M + ADVANCE A SECTOR." 

120 

S = PEEK <0L) / 16: D ■ PEEK 




(DR> 

900 

PRINT «- EG BACK A SECTOR. " 

130 

PAINT ,, DlSC"i; GDSUB 1300 


: PRINT 

140 

POKE SL,5 * 16: POKE DR,D: POKE 

910 

PRINT "N SPECIFY A NEW SECT 


VL,0 


OR, " 

150 

POKE BL,G; POKE BH,B 

920 

PRINT -C SPECIFY A NEW SECT 

1 60 

GOSUB ibiOi DS = 0: GOTO 550 


OR BUT" 

170 

POKE 36,0; POKE 37,22: CALL 

930 

PRINT " DO NOT READ IT IN, 


“ 990 


M : PRINT 

L BO 

CALL - 868 

940 

PRINT ”F PATCH THE CURRENT 

190 

PRINT 


SECTOR" 

200 

PRINT "■ OPTION (TYPE ? ‘ 

950 

PRINT " IN MEMORY. " 


FOR NENUJ 

960 

POKE 32, PEEK (32) - 1: CALL 

210 

POKE SO, 63: PRINT " "i : POKE 


- 990 


50,255 

970 

PRINT "ESC END." 

220 

CALL - 868 

980 

POKE 32,0: POKE 33,40: CALL 

230 

POKE 36,32 


- 990 

240 

CH = PEEK (KB I; IF CH < 128 THEN 

990 

GOTO 170 


240 

1000 

TEXT ; END 

250 

POKE KS,0; POKE 36,0; CALL - 

1010 

POKE 36, 19: POKE 37.2: CALL 


068 


- 990 

260 

IF CH = 212 THEN 300 

1020 

PRINT 11 TRACK " ; : MX = 34: E0SUB 

270 

IF CH == L 94 THEN 390 


1130 

200 

IF CH “ 208 THEN 470 

1030 

IF TS < 0 THEN 1010 

290 

IF CH = 210 THEN 550 

1040 

T = TS: POKE TK, T 

300 

IE CH = 215 THEN 610 

1050 

PRINT " SECTOR ■'! :MX = 15: GO0U8 

310 

IF CH = 171 THEN 670 



320 

IF CH = 173 THEN 700 


1 130 

330 

IF CH = 206 THEN 160 

1060 

IF TS < 0 THEN 1010 

340 

IF CH = 1 93 THEN 780 

1070 

S - TS; POKE SE,S 

350 

IF CH - 191 THEN BOO 

1 000 

POKE 36,0; POKE 37,3: CALL 

360 

IF CH “ 153 THEN lOOO 

4 

- 990 

370 

CALL - 198; GOTO 170 

1090 

CALL “ 868 

380 

DS = 0: GOTO 400 

1 100 

POKE 37,4: CALL - 990 

390 

DS = 120 

1 1 10 

CALL - 868 

400 

POKE 36,0: POKE 37,5: CALL - 

1120 

RETURN 


990 

1130 

CALL - 860 

410 

CALL - 068 

1140 

CH = PEEK C36> : EV = PEEK t 

420 

POKE 37,6; CALL - 990 


37) I PORE 51,120 

430 

POKE 60, DS: POKE 62, D5 + 127 

1 150 

CALL “ 662 



1160 

POKE 36,04: POKE 37, CV: CALL 

440 

POKE 61,8: POKE 63,8 


- 990 

450 

CALL MB 

1170 

PT = 512;CM = PEEK iPT>:TS = 

460 

GOTO 170 


- la IF CH = 141 THEN 1200 

470, 

POKE 36,0: POKE 37,4: CALL - 

1 180 

TS = 0 


990 

1190 

IF CH = 131 THEN END 

480 

CALL - 868 

1200 

CH * CH - 176 

490 

PRINT "ADDR; 

1210 

IF CH 0 THEN 1290 

500 

MX = 255; EOSUB 1130: IF T5 < 

1220 

IF CH > 22 THEN 1290 


0 THEN 170 

i 230 

IF CH < 10 THEN 1250 

510 

AD = IS: PRINT M PATCH; 

1240 

CH = CH - 7i IF CH < lO THEN 

520 

G03UB 1130: IF TS < 0 THEN 4 


1290 


00 

1250 

TS ~ TS * 16 + CH: IF TS > M 

530 

POKE BD + AD, TS: AD = AD + Is 


X THEN 1290 


IF AD 255 THEN 400 

1 260 

PT = pt + 1:CH = PEEK (PTl ; 

340 

PRINT ” - ? : GOTO 520 


IF CH < >141 THEN 1190 

550 

POKE 36,0: POKE 37,4; CALL - 

1270 

POKE HX , TS; CALL PX 


990 

1200 

CALL - 068: RETURN 

560 

CALL - 860 

1290 

CALL - 190; 0PTO 1 130 

570 

POKE PF ,210: CALL DT 

1300 

POKE - 16368,0: CALL - 66 

500 

CALL RD 


6 

590 

IF PEEK. (RP> < >0 THEN 00 BUB 

1310 

PRINT " SLOT S ?:SD = S:MX 


1550 


0: GDSUB 1340: S = SD 

600 

GOTO 400 

1320 

PRINT » DRIVE " j : SD = D:HX = 

610 

POKE 36,0: POKE 37,4: CALL - 


3; GOSUB 1340: D = SD 


990 

1330 

CALL - 068: RETURN 

620 

CALL - 860 

1340 

CH = PEEK (36) 

630 

POKE PF, 21 5: CALL DT 

1350 

POKE 50,63: PRINT SDi : POKE 

640 

CALL WR 


50,255 

650 

IF PEEK <RP> < >0 THEN GDSUB 

1360 

POKE 36, CH 


1550 

1 370 

CH n PEEK C - I 63S4) : IF CH 

660 

GOTO 170 


< 128 THEN 1370 

670 

s = s + 1 : IF S < 16 THEN 730 

1380 

POKE - 16360,0 



1390 

IF CH = 141 THEN 1440 

680 

S ^ O: T = T + li IF T < 35 THEN 

1400 

CH = CH 176 


730 

1410 

IF CH O AND CH < MX THEN 

690 

T - 0: GOTO 730 


1430 

700 S = 5 - 1; IF S > =0 THEN 7 

1420 

CALL - 190: GOTO 1370 


30 

1430 

SO = CH 

710 S * ISsT " T “ l.i IF TO =0 

1440 

PRINT 8Dl; RETURN 


THEN 730 

1450 

GI =* 768: DT = 771 :PX = 775: R 

720 

T = 34 


D = 780: UR = 784 i IP ^ 960a LP 

730 OB = 0 


= 962: HP = 964 

740 

POKE 37,2; CALL - 990 

1460 

CALL 01 

750 

POKE 36,26: POKE HX,T: CALL 

1470 

X " IP: GDSUB 1330: IB = J 


PX 

1400 

1 = LP: GDSUB 1530: LO - J 

760 

POKE 36,36; POKE HX,S: CALL 

L490 

I = HP: GDSUB 1530: HI = 0 


PX 

1500 

SL “ IS * llDR “ IB + 2:VL = 

770 

POKE Tk.T: POKE 5E,S: GOTO 5 


10 + 3; TK - IB + 4:0E = IB +- 


30 


SiBL - IB + EJ:BH = IB + 9:RP 

780 

GOSUB 1010 


= IP ^ 13 

790 

GOTO 400 

1510 

HX = 31 ;PF = 1059 




( continued on next page) 


PRACTICAL COMPUTING October 1983 


149 


PRACTICAL COMPUTING October 1983 


151 






ACT SIRIUS I 
SEEING IS BELIEVING! 


The Act 1 Sirius I is a revolutionary 
concept in personal computing for business, 
bringing a new meaning to the term Price/ 
Performance 

It offers users the 1 6 Bit performance 
normally associated with minicomputers but 
at a microcomputer price. 

And it's backed up by the kind of 0 1 
expertise and service that has made 0 1 one of 
Britain’s top microcomputer Dealers. 

Call us first on 01-228 2207, for a personal 
demonstration of the Act Sinus I. Remember, 
seeing is believing! 


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Disks including CP/M-86, MS-DOS, (Run-time 
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MS-DOS. (Run-time version incorporating 
CP/M-86 emulator) & Microsoft Basic 86 
£3,995 



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Portfolio in stock 

* N B. We are open 
until 6.30 pm weekdays 
and 10 am- 1 pm Sat. 

Call us for an appointment, 
sales/mail order, or simply 
drop in! 

01-228 2207 



I computers 


Southampton House, 192-206 York Road, London SW11 3SA 

TELEX 8954575 CTCLDN 



Please send me a copy of 
your introductory brochure 
and details of the Act Sinus I. 


Name_ 



Address. 


.Tel No:_ 


Occupation. 


Southampton House, 192-206 York Road, London SW11 3SA 

• Circle No. 252 


152 


PRACTICAL COMPUTING October 1983 




Open file: Apple 



Patch 


an excellent 16-sector disc-patch 
program or catalogue analyser is 
submitted by Mark Benson of Tring* Any 
sector of a regularly formatted Apple 
floppy — which excludes tiresome 
commercially screwed discs like VisiCalc 
— may be read, amended, written or 
rewritten, with comprehensive prompts at 
the appropriate point. 

While it vovides a perfect way of 
learning about catalogue and program 
layout if the Write options arc avoided, it is 
a guaranteed way of losing disc data if you 
do not know what you are about. Given 
that you do, Mark Benson has written an 
excellent utility to do it with. 

The associated assembler routine — for 
which I have no source code — is to be 
saved as: 

BSAVE B PATCH n AA0295 t L$01 13 
For use on 13-sector discs the following 
amendments are needed: 

Line 140, *16 becomes *13 
Line 670. <16 becomes <13 
Line 710, “15 becomes =s 12 
Line 1050. =15 becomes =12 


Patch. 








#0295. 03H7 







0295- AS 

3C 

29 






0298- F8 

85 

3C 

38 

A5 

W 

FI 

E5 

3C 

02 A0- AS 

3F 

E5 

3D 

BO 

01 

60 

A5 

02 m- 3C 

20 

□A 

FD 

A2 

02 

20 

4A 

Q2BQ- F9 

AO 

00 

Bl 

3C 

20 

DA 

FD 

02B8- A2 

01 

20 

4A 

F9 

G0 

CO 

OS 

02C0- DO 

Fi 

FO 

02 

00 

00 

A2 

01 

02CB- 20 

4A 

F9 

AO 

00 

Bl 

3C 

09 

02D0- SO 

C9 

AO 

80 

04 

A9 

AO 

BO 

O2D0- 06 

C9 

EO 

90 

02 

E9 

20 

20 

02E0- ED 

FD 

C9 

CO 

oe 

DO 

E6 

A9 

02E8- BD 

20 

ED 

FD 

IS 

A5 

3C 

85 

O2F0- 40 

69 

08 

85 

3C 

A5 

3D 

85 

02F8- 41 

69 

00 

85 

3D 

90 

9C 

60 

0300- 19 

90 

6 b 

A9 

04 

DO 

27 

AS 

0308- IF 

4C 

DA 

FD 

A9 

01 

DO 

02 

0310- A? 

02 

4S 

20 

E3 

03 

85 

49 

0318- 84 

48 

AO 

OC 

68 

91 

48 

20 

0320- E3 

03 

20 

D9 

03 

BO 

06 

A9 

032B- 00 

AO 

OD 

91 

49 

60 

48 

20 

0330- E3 

03 

84 

48 

85 

49 

AO 

04 

0338- Bl 

48 

95 

IE 

C8 

Bl 

48 

85 

0340- IF 

6Q 

85 

49 

A9 

24 

as 

40 

0348- A2 

02 

AO 

03 

18 

B5 

ID 

29 

0350- OF 

08 

18 

69 

BO 

C9 

BA 

90 

0358- 02 

69 

06 

91 

48 

98 

28 

BO 

0360- 09 

as 

IP 

4A 

4A 

4A 

4A 

38 

0368- BO 

E7 

CA 

DO 

DF 

60 

20 

E3 

0370- 03 

SC 

CO 

03 

SD 

Cl 

03 

A9 

0378- B6 

85 

48 

AD 

E5 

03 

85 

49 

0380- AO 

00 

Bl 

48 

DO 

OD 

AS 

C C 

0388- BD 

C2 

03 

A5 

CD 

A6 

CA 

A4 

0390- CD 

90 

OB 

AS 

6D 

n D 

C2 

03 

0398- A5 

6E 

A6 

6F 

A4 

70 

8D 

C3 

O3A0- 03 

SE 

C4 

03 

OC 

C5 

03 

60 


Patch. 

800 

POKE 36,0: POKE 37,6: CALL - 
990 



010 

POKE 35,22: CALL - 936 

to 

IF GO THEN 170 

B2Q 

POKE 35,24 

20 GO = 1 

030 

PRINT " OPTIONS AVAILABLE 

30 KB = - 16304 ; KS = - 1636B:MD 


PRINT 


= 661 

040 

POKE “2,5: POKE 33,35: CALL 

40 

TEXT s CALL - 936 


- 990 

50 

PRINT CHR* (4)1" BLOAD BPATCH 

050 

PRINT "T DISPLAY BYTES 00-7 

F . " 

60 

FRINT ‘16 SECTOR DISC PATCH : 

060 

PRINT "B DISPLAY BYTES GO-F 

F."s PRINT 

70 

PRINT 

870 

PRINT "ft RE-READ CURRENT SE 

SO 

POKE 34,5 


CTOFL - 

90 

GOSUB 1450 

880 

PRINT “W WRITE BACK CURRENT 

100 

b - PEEK 4LP + 11 +2 


SECTOR. PRINT 

no 

BB * B * 128: SB = BB + BB 

890 

PRINT "+ ADVANCE A SECTOR." 

120 

S = PEEK (SLJ / 16;B = PEEK 




(DR) 

900 

PRINT "- GG BACK A SECTOR. 11 

130 

PRINT "DISC"; ; GOSUB 1300 


: PRINT 

140 

POKE SL, 5 * 16; POKE DP. D: POKE 

910 

PRINT "N SPECIFY A NEW SECT 


VL , 0 


OR. " 

150 

POKE BL, 0; POKE BH,B 

920 

PRINT p, C SPECIFY A NEW SECT 

160 

GOSUB 1010; DS - 0: GOTO 550 


Oft BUT" 

170 

POKE 36,0; POKE 37,22: CALL 

930 

PRINT ,f DD NOT READ IT IN. 


- 990 


PRINT 

ISO 

CALL - 060 

940 

PRINT ,h P PATCH THE CURRENT 

190 

print 


SECTOR" 

200 

PRINT ,r OPTION (TYPE 7 

950 

PRINT ,f IN MEMORY* " 


FOR MENU) 

960 

POKE 32, PEEK (32) - 1: CALL 

210 

POKE 50,63; PRINT " %: POKE 


- 990 


50, 255 

970 

PRINT "ESC END," 

220 

CALL - 060 

990 

POKE 32,0: POKE 33,40: CALL 

230 

POKE 36,32 


- 990 

240 

CH = PEEK (KB): IF CH < 128 THEN 

990 

GOTO 170 


240 

1000 

TEXT ; END 

250 

POKE KS, 0: POKE 36*0: CALL - 

1010 

POKE 36,19: POKE 37,2: CALL 


B6B 


- 990 

260 

IF CM = 212 THEN 380 

1 020 

PRINT " TRACK " ; ; MX = 34; GOSUB 

270 

IF CH = 194 THEN 390 


1130 

280 

IF CH = 200 THEN 470 

I030 

IF TS 0 THEN 1010 

290 

IF CH = 210 THEN 550 

1040 

T = TS; POKE TK, r 

300 

IF CH - 215 THEN 610 

1050 

PRINT 1 SECTOR MX = 15: GOSUB 

310 

IF CH = 171 THEN 670 



320 

IF CH = 173 THEN 700 


1130 

330 

IF CH =206 THEN t60 

1060 

IF TS < 0 THEN 1010 

340 

IF CH = 195 THEN 700 

1070 

5 = TS: POKE SE,S 

350 

IF CH = I 91 THEN 000 

1 080 

POKE 36,0; POKE 37,3: CALL 

360 

IP CH = 155 THEN 1000 


- 990 

370 

CALL - 19S; GOTO 170 

1090 

CALL - 860 

380 

DS = 0; GOTO 400 

1 100 

POKE 37,4: CALL - 990 

390 

DS = 120 

1 1 10 

CALL - 860 

400 

POKE 36,0; POKE 37,5: CALL - 

1 120 

RETURN 


990 

1130 

CALL - 868 

410 

CALL - 060 

1 140 

CH - PEEK <363 :CV - PEEK ( 

420 

POKE 37,6: CALL - 990 


37) : POKE 51, 120 

430 

POKE 60, DS: POKE 62, DS + 127 

1 150 

CALL - 662 



1 160 

POKE 36. CH; POKE 37, CV: CALL 

440 

POKE 61, B: POKE 63, B 


- 990 

450 

CALL MD 

1 170 

FT = 31 2: CH = PEEK (PT> ;TS = 

460 

GOTO 170 


- Ii IF CH = 141 THEN 1280 

470. 

POKE 36,0: POKE 37,4: CALL - 

1 100 

rs « 0 


990 

1 1 90 

IF CH = 131 THEN END 

480 

CALL - 860 

1200 

CH = CH - 176 

490 

PRINT rt AD OR: '■? 

1210 

IF CH - 0 THEN 1290 

500 

MX = 255: GQSLTB 1130: IF TS < 

1220 

IF CH > 22 THEN 1290 


0 THEN 170 

1230 

IF CH < 10 THEN 1250 

510 

AD = TS: PRINT PATCH; 

1240 

CH - CH - 7*. IF CH < 10 THEN 

520 

GOSUB 1130: IF TS < 0 THEN 4 


1290 


00 

1250 

TS = TG * 16 + CH; IF TS > H 

530 

POKE BB + AD.TStAD = AD + 1: 


X THEN 1290 


IF AD 255 THEN 400 

1260 

FT = FT * 1 ; CH = PEEK (FTP: 

540 

PRINT " " ; : GOTO 520 


IF CH < > 141 THEN U90 

550 

POKE 36,0: POKE 37,4: CALL - 

1270 

POKE HX,TS; CALL PX 


990 

1280 

CALL - 860: RETURN 

560 

CALL - 068 

1290 

CALL - 198; GOTO 1130 

570 

POKE PF, 210: CALL DT 

1300 

POKE - 16368,0: CALL - 86 

580 

CALL RD 


8 

390 

IF PEEK CRP ) > 0 THEN GOSUB 

1310 

PRINT " SLOT 11 ; : SD - S:MX => 


1550 


0; GOSUB 1 340; S = SD 

600 

GOTO 400 

1320 

PRINT 11 DRIVE ■' ;:SD = D:MX = 

610 

POKE 36,0: POKE 37,4: CALL 


3: GOSUB 1340: D = SD 


990 

1330 

CALL - 068: RETURN 

620 

CALL - 060 

1340 

CH = PEEK (36) 

630 

POKE PF, 215: CALL DT 

1350 

POKE 50,63= PRINT SD? : POKE 

640 

CALL WR 


50,255 

650 

IF PEEK (ftp) < 0 THEN GOSUB 

1360 

POKE 36, CH 


1550 

1370 

CH « PEEK C - 16304): IF CH 

660 

GOTO 170 


< 120 THEN 1370 

670 

S ** S + L: IF S < 16 THEN 730 

1380 

POKE - 16368,0 



1390 

IF CH = 141 THEN 1440 

690 

S = 0:1“ T * Is IF T < 35 THEN 

1400 

CH = CH - 176 


730 

1410 

IF CH > 0 AND CH C MX THEN 

690 

T = 0: GOTO 730 


1430 

700 

s = S - l: IF s > = 0 THEN 7 

1420 

CALL - 190: GOTO 1370 


30 

1430 

ED = CH 

710 

S 15:T *» T - is IF T > =iO 

1 440 

PRINT SD; : RETURN 


THEN 730 

14S0 

GI = 76B:DT = 771 :PX = 775= R 

720 

T - 34 


D = 780: Wft = 784: IP = 960: LP 

730 

D5 = 0 


= 962: HP = 964 

740 

POKE 37,2: CALL - 990 

1460 

CALL, SI 

750 

POKE 36,26; POKE HX,T; CALL 

1470 

I = IP; GOSUB 1530: IB - J 


PX 

14 BO 

I a UP: GOSUB 1530; LO = J 

760 

POKE 36,36: POKE HX,0: CALL 

1.490 

1 = HP: GOSUB 1530; HI = J 


PX 

1500 

SL = IB + I: DR = IB + 2:VL = 

770 

POKE TK,T: POKE S£,S: GOTO 5 


IB + 3: TK IB + 4: BE = IB +- 


50 


3: BL = IB * 8:BH = IB * 9: ftp 

790 

GOSUB 1010 


f IB + 13 

790 

GOTO 400 

1510 

HX = 31=PF = 1059 




(continued on next page) 


PRACTICAL COMPUTI NG October 1983 


149 





Sub exterminator. 

*5600. 5920 

5600- 07 OO 10 00 03 01 F4 01 

5608- 70 02 F5 02 09 03 ID 03 

5610- 4B 49 49 49 49 49 29 2D 

5618- 2D F5 DB ID 4D 49 DE DB 

5620- 2D 2D 2D F5 DB IB 2D 2D 

5620- 2D DE DB 2B 2D 2D 6D 49 

5630- 49 49 49 49 29 DE DB DB 
5630- DB DB DB DB DB DB DB DB 
5640- DB IB 4D 49 OD 2D 2D 2D 
5640- 2D 2D 2D 2D 2D 2D 2D 2D 
5650- 2D 2D 2D F5 DB DB DB DB 
5650- DB D0 DB DB DB DB DB DB 
5660- OD 2D OD OD 2D 2D 2D 2D 
5668- 2D 2D 2D 2D 2D 4D 49 4D 
5670- 29 DE DB DB DB DB DB DB 
5678- DB DB DB DB DB DB 2D 20 
5680- 2D 2D 2D 2D 6D 49 49 49 
5688- 49 49 49 4D FI DB DB DB 
5690- DB DB DB DB DB DB DB DB 
5690- DB DB 2D 2D 2D 2D 6D 49 
56 AO- 49 49 4D 09 4D 09 4D 09 
56A0- 2D OD F5 DB DB DB OB DB 
56B0- DB DB DB DB DB DB DB DB 
56B8- 4D 49 49 49 49 49 49 49 
56C0- 49 49 49 49 4D DE DB DB 
5628™ DB DB DB DB DB DB DB DB 
56D0- DB DB 6B 49 49 49 49 49 

56D0- 49 49 49 49 49 49 49 F5 

56E0- DB DB DB DB DB DB DB DB 

56E8- DB DB DB DB IB 2D 2D 2D 

56F0- 2D 2D 2D 2D 2D 2D 2D 2D 

56F8- 2D 2D 2D 2D 2D 2D 2D 2D 

5700- 4E 09 00 48 49 49 49 49 

5700- 49 09 2D 2D 2D DE DB 6B 

5710“ 49 FI DB IB 2D 2D 2D DE 

5718- DB 2B 2D 2D F5 DB DB DB 

5720- DB DB DB DB IB 6D 49 49 

5728“ 49 49 49 2D 2D 2D DE DB 

5730- DB DB DB DB DB DB 2B 2D 

5738- 2D 2D 2D 2D 2D 2D 2D 2D 

5740- 2D 2D 2D 2D 6D 69 49 FI 

5748- DB DB DB DB DB DB DB DB 

5750- DO DB DB DB 6D 09 4D 49 

5758- 2D 2D 2D 2D 2D 2D 2D 2D 

5760- 6D 69 2D OD DE DB DB DB 

5760- DB DB DB DB DB DB DB DB 

5770- 6B 09 4D 49 49 49 49 49 

5778- 09 2D 2D 2D 2D 2D 2D F5 

5780- DB DB DB DB DB DB DB DB 

578B- DB DB DB DB 6D 2D 4D 09 

5790- 4D 09 4D 09 4D 49 49 09 

5798“ 2D 2D 2D 2D F5 DB DB DB 

57 AO— DB DB DB DB DB DB DB DB 

57A8- DB IB 4D 4D 49 49 49 49 

57B0- 49 49 49 49 49 49 49 DE 

57B8- DB DB DB DB DB DB DB DB 

57CQ- DB DB DB DB 2B 4D 49 49 

57CS- 49 49 49 49 49 49 49 49 

5 7 DO- 49 09 DE DB DB DB DB DB 

57D8- DB DB QB DB DB DB DB 2D 

57E0- 2D 2D 2D 2D 2D 2D 2D 2D 

57E8- 2D 2D 2D 2D 2D 2D 2D 2D 

57FQ- 2D 2D OE 00 4B 49 49 29 

57FB- IE F5 F5 DB 2D 2D 2D 2D 

5800- 6D 69 09 4D Fl DB DB DB 

580B- DB DB DB DB 2fi 2D 2D 2D 

5010“ 2D 2D 2D 2D 2D 2D 2D 2D 

5018- 2D F5 DB DB DB DB DB DB 

5020- DB DB IB 6D 49 49 OD 4D 

5028“ 49 OD 4D 49 49 DE DB DB 

5830“ DB DB OB DB DB DB DB 2D 

5838- 4D 49 09 OD 4D 4D OD 4D 

5840- 49 49 F5 DB DB DB DB DB 

5848- DB DB DB DB 2B 4D 49 09 

5850- 2D 4D 49 OD 4D 49 49 DE 

5858- DB DB DB DB DB DB DB DB 

£860- 28 2D 2D 2D 2D 2D 2D 2D 

5068- 2D 2D 2D 2D 2D 75 09 OO 

5870“ 4B 49 49 49 49 49 49 49 

5078- F5 F5 F5 DB DB DB DB DB 

5800- 6B 09 4D 69 29 2D 2D 2D 

5888- 2D DE D0 DB DB DB DB DB 

5890- DB 2D 2D 2D 2D 2D 2D 2D 

'5898- 2D 2D 2D 2D 2D 2D DE DB 

5BA0- DB DB DB DB DB DB DB 6B 

50AS“ 49 49 69 4D 49 2D 4D 49 

5BB0— 09 F5 DB DB DB DB DB DB 

59BS“ DB DB DB 28 4D 49 49 OD 

5BC0- 4D 4D OD 4D 49 09 2D DE 

5088- DB DB DB DB DB DB DB DB 

58DO- DB 4D 49 49 OD 4D 49 OD 

58DS- 4D 49 09 F5 DB DB DB DB 

58E0- DB DB DB DB IB 2D 2D 2D 

50E8- 2D 2D 2D 2D 2D 2D 2D 2D 

5BF0- 2D 2D 4E 01 OO 4B FI 8B 

58FB- OD DE 2B F5 IB 2D 2D DE 

5900“ 2B F5 IB OD OD DE 4G 01 

5908- 00 4B 09 IE 2D DE 2D DE 

5910- 2D DE 2D DE 20 2D F5 DB 

5918- 6B OD OD OE 00 FF OO 00 

5920“ 00 
*3DOB 


{continued from previous page) 


1520 

RETURN 



1530 

j = FEEk (1 + U: IF j ; 

12 


7 THEN J = J ~ 256 



1540 

J - j # ue: j = j *- 

J + 

PEEK 


(I): RETURN 



1550 

PRINT "ERR 



1560 

POKE HX, PEEK tRP): 

CALL 

PX 

1570 

PRINT " AT S'; PEEK 

(SL) 

/ 


16;" D"; PEEK SDR) ; " 

TRK 


15 BO 

POKE HX , PEEK (TK) ; 

CALL 

PX 

1590 

PRINT " SEC " * 



1600 

POKE HX, PEEK fSE): 

CALL 

PX 

1610 

PRINT 



1620 

RETURN 




Sub exterminator 

The graphics on this game from Mark 
Heather of Cudham are excellent, and the 
play is exciting once the controls have been 
mastered. Having tried For some time, both 
looking at the listing and running the 
program, 1 can still not deduce the 
submarine's strategy or quite how to stay 
afloat for any length of time, but that is 
what makes it so interesting. Mr Heather 
does not say what utility he used to generate 
his graphics elements, but they are quite 
superb. 


Sub exterminator. 

1 0 REM SUB-E X TERM I NATOS 
15 REM BY Ji. 3. HEATHER 
20 REM ON APPLE 2 
25 REM 30/4/83 
30 REM 

35 IF PEEK (220161 “ 7 AMD PEEK 
(220171 = O THEM GOTO 45 
40 PRINT CHRS {4); "BLOAD SUB SH 
APES" 

45 POKE 232,0: POKE 233,86 
50 CLEAR : GOSUB 6lSs SR : TEXT 

52 ONERR GOTO 5000 
55 M* “ H *#* YOU HIT *** 

♦*#YOU HIT ***" 

60 IV* " " +*+ YOU HIT 

**» " 

65 HOME : PRINT "INSTRUCTIONS;-" 

: PRINT 

70 PRINT ; PRINT "YOU HAVE TO LI 
NE YOUR BOAT WITH THE BUB" 

75 PRINT "THEN LAUNCH A MINE, BU 
T YOU ONLY HAVE" 

BO PRINT "10 MINES ! ! ! "i PRINT 
B5 PRINT "THE SUB CAN ALSO BLOW 
YOU OFF THE FACE" 

90 PRINT "OF THE EARTH , SO BEWA 

RE AND GOOD LUCK ■ " : PRINT : PRINT 

"CONTROLS:-": PRINT 


95 

PRINT "LEFT ARROW 

MOVE LE 


FT" 


ICO 

PRINT "RIGHT ARROW 

- MOVE R 


ISHT" 


105 

PRINT "SPACE BAR 

= MINE 


LAUNCH" 


no 

PRINT 


115 

PRINT "ANY OTHER KEY 

TO MOVE 


SHIP TO RANDOM " : PRINT 41 PQ 
' SIT ION AND ANCHOR" 

120 INVERSE : PRINT "WARNING YOU 


LOSE A MINE AFTER DOING THI 
S";: NORMAL ; PRINT 
125 FLASH : PRINT "PRESS SPACE B 
AR TO START"? ; NORMAL 
130 GET A* 

135 REM START OF GAME 
140 HGR : HCOLOR— 3 s SCALE= Is ROT= 
0:W - 10; REM SET GRAPHIC 
8 AND NO. OF MINES 
145 HOME 

ISO VTAB 21: PRINT "MINES = "JW? 

155 PRINT TAB( 30) S "SCORE » "JS 
C 

160 8 = INT ( RND (1) * 80 J * 3 + 

10 

165 R = 3 

170 IF 8 < SM THEN 8=4 
175 E = PEEK t - 163841a OX = Xi VTAB 
21: PRINT "MINES = *;W;i PRINT 
TAB ( 30 )J "SCORE - "fSCaE = 

E ~ 120: IF E = 0 THEN X - X 

- e 

ISO IF E = 21 THEN X =■ X + 8 

105 IF E = 32 THEN GOTO 260 

190 IF E > 32 THEN X * INT < RND 
( 1 ) * 235 + !>■ POKE - 1 636 
8,0:W = W - 1* IF W = 0 THEN 
GOTO 550 

195 IF X < 1 THEN X = 1 
200 IF X > 235 THEN X = 235 
205 IF X > OX THEN Z = 1 

210 IF X < OX THEN Z = 2 

21 S IF RND (I) > .85 THEN GOTO 
400 

220 DRAW Z AT X , 3 

225 POKE PI, INT ( RND (11 * 30 * 

100): POKE DU, 4: CALL NO: HPLOT 
0,15 TO 279,15a IF SM < S THEN 
D ^ SM + 5 

230 IF SM > 8 THEN D ™ SM - 3 
235 SM = Da DRAW R AT 5M* ISOs IF 
SM > tS - 3> AND SM < (S + 3 
> THEN HGR : GOTO 160 


240 VTAB 21; PRINT "MINES = ";W; 

: PRINT TAB ( 301; "SCORE = " 
t SC: XDRAW Z AT X,3: XDRAU R 
AT SM, 150: GOTO 175 ! 

245 REM 

250 REM SHIP FIRING 
255 REM 

260 DRAW Z AT X,3: XDRAW R AT SM 
,150: HPLOT X + 10,5: FOR A ~ 

10 TO 150 STEP 15: DRAW 5 AT 
X + 1 0, A 

265 POKE PI , SM: POKE DU, 3; CALL 
NO 

270 XDRAW R AT 3M, 150 
275 IF SM < S THEN B - SM +■ SC 
200 IF SM > 3 THEN D - SM — SC 
285 SM = Dl DRAW R AT SM,150; XDRAW 
R AT SM, 150 

290 IF SM > iS - 5) AND SM < (8 + 

5) THEN 8 = INT ( RND (1) * 

86) * 3 + 10; DRAW 1 AT X,3: 

HPLOT 0,15 TO 279, 15f ft — “ST 
IF S < SM THEN R = 4i DRAW 
R AT SM, 150 

295 VTAB 21; PRINT "MINES = "jW; 

: PRINT TAB ( 30); "SCORE = " 

;sc 

300 XDRAW 5 AT X + IO,A 
305 XDRAW R AT SM, 150 
310 NEXT A 

315 IF X + ID > (SM - 1) AND X +■ 

10 < (BM + 26) THEN 345 
320 W - W - la IF W = 0 THEN GOTO 
550 

325 HGR : GOTO 175 
330 REM 

335 REM HIT SUB 
340 REM 

345 GR : HOME : SC =SC + 1 
350 PRINT "YOU HIT THE SUB . SCO 
RE » "f SC 

355 FOR 0 = l TO 15 STEP 2i POKE 
DU, Is FOR C “ 1 TO 5;F = INT 
( RND (1) * 15) + 1: POKE PI 
,F: CALL NO: NEXT C 
360 COLDR= J: FOR H = 0 TO 39a POKE 
PI, 40 - H; CALL NO; HLIN 0,3 
9 AT H; NEXT H: NEXT j 
365 TEXT ; HOME : FLASH ; FOR V = 

I TO 24; POKE PI,V * 2s POKE 
DU, 10: CALL NO: PRINT M*;N*; 

: NEXT V: NORMAL 

370 FOR I = 1 TO 20: POKE PI ,255 
- I; CALL NDs POKE 32,20 “ 

I; POKE 33,2 * I: PRINT i PRINT 
: NEXT : FOR I = 1 TO 24: POKE 
PI, SC * 10: CALL NO: PRINT s 
NEXT 


375 

X * INT ( RND U) * 35) 

+ 1 

380 

HGR ; GOTO 175 


385 

REM 


390 

REM SHIP HIT 


395 

REM 


400 

DRAW R AT SM, ISO; DRAW 1 AT 
X,3 

405 

FOR A = 150 TO 3 STEP - 

- 5 1 : 


6 AT SM + 10, A; XDRAW 6 
M + 10, Ai NEXT A 

AT S 

410 

IF BM + iO > X AND SM + 
(X + 40) THEN GOTO 425 

lO C 

415 

HGR 


420 

GOTO 175 


425 

TEXT : HOME ; FDR A = 1 
2 

TD 1 

430 

>RrNT "Y Y 000 U U 80S 
TTT H H III TTT !" 

000 

435 

POKE PI, 20: POKE DU, 50: 
NO 

CALL 

440 

PRINT "Y Y 0 0 U U G G 
T H H I T \ “ 

O 0 

445 

POKE FI , 45 a CALL NO 


450 

PRINT " YY 0 O U U G 

T H H l T 

D O 

455 

POKE PI, 50: CALL NO 



150 


PRACTICAL COMPUTING October 1983 


Open file: Apple 1 


HGR strings. 

410 

REM *** NOW READY TO WRITE 



420 

HGR ; REM TEXT 

1 0 

REM HGR STRINGS **+ W.K 

430 

PRINT : PRINT : PRINT : PRINT 


-HO 


"GIVE TEXT STRING-/ CLR SCRN 

20 

DIM CA (237, CH <40, 61 


; RET TO EXIT"; INPUT Si 

30 

ONERR GOTO 750 

440 

IF 54 < > "" GOTO 460 

40 

FOR I - 0 TO 5; READ E(3>; NEXT 

450 

RETURN 



460 

IF Si - THEN HER : GOTO 

50 

DATA 1 , 2,3,5* 6,7 


430: REM ** -V" TD WIPE SCR 

60 

REM **# SET CORE ADDRESS FOR 


een 


LINE 

470 

K — INT ( RND (11 * 25) :L - 

70 

FDR I - O TD 23 


[NT ( RND <U #-201 

00 

READ CA( n : NEXT I 

480 

GDSUB 490: GOTO 430 

90 

DATA 0192, 8320 .0448, 8576 , 870 

490 

N = LEW (Si? : REM ■** WRITE 


4,0832*0960,9088 



100 

DATA 0232,8360 * 8408, 06 1 6 r @7 

500 

IF N + K >39 THEN N = 39 - 


44,8872,9000*9120 


K 

110 

DATA 8272, 8400,0520, 0656,87 

510 

FOR I » 1 TO h 


84,8912,9040, 9160 

520 

set = MID* (Si,n: REM *** 

120 

REM *** LOAD BIT PATTERN 


READ EACH CHARACTER IN STR IN 

130 

FOR I = 0 TD 48 


G 

140 

for K = 0 TO 6 

530 

J = ASC (SB*) s J = J - 43 

150 

READ CH(1,KJ : NEXT K 

540 

IF J > - i AND J < 40 BOTQ 

160 

NEXT I 


570 

170 

GOTO 390 

550 

J = 48 

180 

DATA 0,0,8,28,8,0,0,0*0*8*8 

560 

REM *** WRITE CHARACTER 


,8,4,0*0*0,0,28*0,0,0 

570 

FDR M - 0 TO 6 

190 

DATA 0,0*0*8,0,0,0,0,32,16* 

580 

A = CA(L> + K + M # 1024 - 1 


0,4, 2,0 

590 

POKE A + [ , CH f J , H) 

200 

DATA 20,34*34,34.34,34,20,8 

600 

NEXT M 


,8, 8, 8*8, 8,0, 20 , 34 ,16,8,4,2, 

610 

NEXT l 


62 

620 

RETURN 

210 

DATA 28,34,32.24*32,34,20,2 

030 

TEXT : HOME : REM *** MENU 


4,20,18* 18,62, 16, 16,62,2,2,3 

64Q 

VTA8 5 


0*32,34,28 

650 

PRINT "HGR TEXT STRING GENER 

220 

DATA 28,34 ,2,30, 34, 34, 28, 62 


ATOR" s PRINT ; PRINT "BY W.K 


*32,32, 16, 0* 4, 2, 20, 34, 34, 20, 


*HO-MAY, 1983": PRINT ; PRINT 


^4 S4 28 

230 DATA ’20,34,34,60,32,34,28,0 

,8 f 0,0,0, 0*0 

240 DATA 0,0,0,0,0,3,4,0,16*8,4 
,S, 16,0,0,0* 28 ,0,20,0,0 
230 DATA 0,4,0, 16,8, 4,0, B, 20*20 
, 16,8,0,0, 8,20, 23,20, 12,20,8 

260 DATA 8,28,34,34,62,34,34 
270 DATA 30,34,34,30, 34 , 34 „ 30 
200 DATA 20,30,2,2,2,30,20 
290 DATA 30, 34,34,34, 34, 34, 30 
300 DATA 62,2,2*30,2,2,62,62,2, 
2,30,2,2,2 

310 DATA 28,34,2,2,58,34,28,34, 
34,34,62,34,34,34,8,8,8,8,0, 
8,8, 32, 32, 32, 32, 34 , 34* 28 
320 DATA 50,10,6,6*10,26,50,2,2 
,2,2,2,2*62*34,54,42,42*34,3 
4 , 34,34,30, 42, 42, 42, 50, 34 
330 DATA 28 , 34 , 34334 , 34 , 34,20 
340 DATA 30,34,34,30,2,2,2,28,3 
4,34,34, 42, 26, 44, 30, 34 , 34,30 
,10,18,50 

350 DATA 28,34*2,28,32,34*20,62 
,6*8,8*8,8*8,34,34*34,34,34, 
34,28 

360 DATA 34,34,20,20,28,8,8*34, 
34,42,42,62,54 ,34*34,54, 20, 8 
,20,54*34 

370 DATA 34,34,20,28*8*8.8,62,3 
2* 16, 28.4*2*62 
300 DATA 0,0, 0,0,0, 0,0 
390 GQSUB 760: GQSUB 630s GOTO 7 
10 

400 PAINT : PRINT : PRINT t PRINT 


660 

670 


690 

700 

710 


720 

730 


740 

750 


780 

790 


PRINT "THIS PROGRAM GENERATE 
S TEXT STRINGS'" i PRINT "IN H 
GR MODE" 

PRINT "THIS IS A DEMONSTRATl 
ON”; PRINT i PRINT "OPTIONS: 

PRINT 1 PRINT "O-MENLTi PRINT 
" 1-TEXT STRINGS: /TO CLEAR: RE 
T TO EXIT" 

PRINT 11 2-SINE DEMO 1 PRINT H 
3-RANDOM WALK"! PRINT "4-AUT 
0 STRINGS" t PRINT "5-AUTB SE 
OLlENCE" 1 PRINT "9 -END" 

VTAB 24 

PRINT : RETURN 

PRINT 11 CHOOSE OPTIONS-" i PRIJJT 

"O-MENU; 1 -TEXT STR; 2-SINE OE 

MO 11 ; PRINT "3-RANDOM WALK: 4- 

AOTO TEXT ; 5-SEQ; 9-EXIT”; GET 

Ts T = T + 1 

IP T > 6 THEN END 

ON T GO0U0 630,420,780,1040, 

1270,1310 

GOTO 7T0 

PR I NT " ERROR-REENTER ! " ; GOTO 
710 

R*<0> - "START" 1 R4 1 1 > - "NO* 1 
'■(R*<2) = "NO* 2" : R4 (3) - "NO 
.3";R*(4J = "NQ. 4 11 
R*<5> - H N0*5"tR*{6> = "NO. 6" 
:R*<75 = "NQ.7":R*(03 = "END 
"1 RETURN 

N - 1 NT { RNB ( 1 > * 6> 

IF <N > - 1 AND N < 6) GOTO 

010 
N - 0 


810 HCOLOR= C (N) 

020 PRINT ; PRINT ; PRINT "SINE- 
DEMO" 

830 XO - 0 

040 X = 0 

B50 V - X 

060 HGR 

070 VO = X0 

000 PI = 3- 14139 

090 HPLOT 4,00 TO XO, VO + 80 

900 FOR I = I TO SO 

910 X - X + 3 

920 V ■ BO + VO + I NT MO * SIN 
tl # 0.1 * Pill 
930 HPLGT TO X,Y 
940 NEXT I 
9S0 N = N + 1 
960 IF <N < 51 GOTO 900 
970 N = 0 
900 HCOLOR= C(N) 

990 X = XD + 6 
1000 VO = X / 2 
1O10 XO - X 

1020 IF (XO < 261 GOTO 090 
1030 K ■= lOtL = 2;5> = "SINE FUNC 
T 1 ON " : GDSUB 490; RETURN 
1040 HGR i REM **# RANDOM WALK 
1050 N =■ INT f RND (11 * 6J 
1060 HCQLQR= CtNi: FOR I a 70 TO 

90s HPLOT 100. I TO 120,Il NEXT 


1070 

1000 


1090 
1100 
mo 
Li 20 

1 130 
11 40 
1150 

1160 


1100 

1190 

1200 

1210 

1220 

1230 

1240 

1250 

1260 


1270 

1200 


1300 

1310 


1 TO 100 
INT U9 


• RND C 1 1 


INI (19 * RND (1J 


PRINT ; PRINT : PRINT "RAND 
OH WALK" 

MM = INT ( RND (1) * 61 :K = 

17 iL = 11? 5* = "START": GDSUB 
490 

FOR P = 1 TO 7 
HCOLDR= G(NN) 

HPLOT 110,80 
XO = 110 
VO - 80 
F OR F 
X = XQ + 
i - 9 
¥ - YO + 

> - 9 

IF (X < 0) OR (X > 220 > GOTO 
1230 

IF <¥ < 0) DR (V > 1501 GOTO 
1230 

HPLDT TO X , Y 
XD = X 
VO ^ V 
NEXT F 
NN = NN + 1 
IF (NN < 6i GOTO 1260 
NN “ 0 

K - INT (XO / 7 + 1UL ■ INT 
(VO / 8 + DsSS * R*(PJ; GUSUB 
490s NEXT Ps RETURN 
HGR ; REM *#* RANDOM TEXT 
VTAB 24: PRINT ; PRINT : PRINT 
"RANDOM TEXT" 

FOR P - 1 TO 20i K “ INT ( RND 
fl) # 23 + i > 1 L = INT ( RND 
<1J * 20 + DtV - INT < RND 
til * 9>:B* - RStVJs GQSUB 4 
90s NEXT P: RETURN 
FOR PS ■ 1 TO 5000s NEXT 1 RETURN 
GQSUB 630: GDSUB 1300; GDSUB 
700s GDSUB 1300; GDSUB 1040: 

GDSUB 13001 GDSUB 1270; GDSUB 
1300: RETURN 


HGR strings 

The Apple high-resolution graphics 
mode is limited by the lack of any 
dedicated character set for user 
applications such as captioning of the 
graphics display. This has resulted in more 
reinventing of wheels of so many shapes 
that I have long since lost count of how 


many have come my way. However, this 
utility from Mr W K Ho of Cheltenham is 
particularly attractive and commands 
attention. 

Though comparatively short it compiles 
a character set by specifying each character 
in a bit pattern occupying a seven-by-eight 
matrix which corresponds to the size of 


each screen character in the Text mode. The 
starting addresses of each print line within 
HGR are also identified. 

Various self-documented options are in- 
built to demonstrate different comb- 
inations of graphics and text. The 
appropriate areas of code may be included 
within user programs as desired. Q 


460 

PRINT " Y 0 0 U U 

G e 

0 0 

550 

FOR A => 1 TO 20; POKE DUR,5: 

465 

470 

T HHH I T ! ” 

POKE PI ,55t CALL NO 
PRINT " Y □ O U U 

GOG 

□ □ 


FDR B = 15 TO 1 STEP - I: POKE 
PIT, 0: CALL NOISE; NEXT Bs NEXT 

A 


T H H I T ! 11 



555 

FDR A = 1 TO 255 i POKE DUR, 1 

475 

POKE PI ,60: CALL NO 




; POKE PI, A: CALL NO; NEXT A 

480 

PRINT « Y O 0 U U 

G 

0 0 


; TEXT i HOME 


T H H I T ! H 



560 

FOR A = 1 TO 24 

485 

POKE PI, 65; CALL NO 



565 

PRINT "GAME OVER" i 

490 

PRINT M Y 000 UUU 

G 

□DO 

570 

INVERSE ; PRINT H SAME OVER 


T HH 111 T I" 




"i ; NORMAL 

495 

POKE PI, 70; CALL NG 



575 

PRINT "SAME OVER" ; 

500 

NORMAL 



580 

FLASH ; PRINT 11 GAME OVER "j 

505 

IF fl = 9 THEN HOME 

: FLASH 


: NORMAL 





5B5 

NEXT A 

510 

IF A - 10 THEN INVERSE 


590 

PRINT "YOU RAN OUT OF MINES, 

515 

IF ft ( 9 THEN PRINT 




BUT SCORED "|SCJ" FTS-" 

520 

NEXT A 



595 

END 

525 

PRINT "YOU LIVED TO 

SCORE "i 

600 

REM 


ECS" POINTS" 



605 

REM MUSIC LOCATIONS 

530 

END 



610 

REM 

535 

REM 



615 

POKE 768,160: POKE 769,255; POKE 

540 

REM GAME OVER 




770, 162 

545 

REM 



620 

POKE 771,160; POKE 772,202; POKE 


773, 20 s 

623 POKE 774,253s POKE 775,173; POKE 
776, 40 

630 POKE 777,192; POKE 778,136s POKE 
779, 200 

635 POKE 780, 245 i POKE 781,96 
640 ND - 760s REM NOISE ROUTINE 
645 PI - 771 1 DU - 769: REM PITCH 
& DURATION ROUTINES 
650 RETURN 
5000 FOR A - 1 TO 50 
5010 POKE PI, A; POKE DU, 250 - A: 

CALL NO 
5020 NEXT A 
5030 TEXT ; HOME 

5040 PRINT "SILLY": PRINT ”==-»= 

M 

5050 PRINT : PRINT "<R>UN , (G)U 
IT >>>?"$ : GET P* 

5060 IF P* - "R” THEN CLEAR 1 GOTO 
40 

5070 IF P* * "0" THEN HOME 1 END 
5080 GOTO 3030 


PRACTICAL COMPUTING October 1983 


151 







The Act 1 Sirius I is a revolutionary 
concept in personal computing for business, 
bringing a new meaning to the term Price/ 
Performance. 

It offers users the 1 6 Bit performance 
normally associated with minicomputers but 
at a microcomputer price. 

And it's backed up by the kind of 0 1 
expertise and service that has made 0 1 one of 
Britain's top microcomputer Dealers. 

Call us first on 01-228 2207, for a personal 
demonstration of the Act Sirius 1. Remember, 
seeing is believing! 


* ACT Sirius 1 128K RAM with 1 2Mb S/S 
Disks including CP/M-86, MS-DOS, (Run-time 
versions) & Microsoft Basic 86 £2 r 195 

* ACT Sirius 1 1 28K RAM with 2 4Mb D/S 
Disks including CP/M-86, MS-DOS. (Run-time 
versions) & Microsoft Basic 86 £2 ,696 

* ACT Sirius 1 256K RAM with 2 4Mb D/S 
Disks including CP/M-86, MS-DOS, (Run- time 
versions) & Microsoft Basic 86 £2 ■ 8 95 

* ACT Sirius 1 256K RAM with IQMb 
Winchester and 12Mb D/S Disk including 
MS-DOS, (Run-time version incorporating 
CP/M-86 emulator) & Microsoft Basic 86 
£3,995 


# Full Peripheral & Software 
Portfolio in stock 

4= N B We are open 
until 6.30 pm weekdays 
and 10 am- I pm Set. 

Call us for an appointment, 
sales/mail order, or simply 
drop in! 

01-228 2207 


Southampton House, 192-206 York Road, London SW11 3S A 

TELEX: S9S4575CTCLDN 


Please send me a copy of 
your introductory brochure 
and details of the Act Sirius I. 


Name.. 


Address _ 


. Tel No:. 


Occupation. 


Southampton House, 192-206 York Road, London SW11 3SA 


• Circle No. 252 


152 


PRACTICAL COMPUTING October 1983 



SOFT OPTION SOFTWARE CENTRE 


When you’re thinking software, think Soft Option first. Chances 
are we’ll have the right product, in the right format, on the shelf in 
quantity. 

We despatch fast from stock. We also offer a dealer pricing 
system to suit individual needs with cumulative discounts available. 

Finally, we know a bout software— we can give you technical 
support when it's needed. 

So make Soft Option your first call. We'll soon become your first 
choice. 


MACHINE FORMATS INCLUDE: 



PROGRAMS INCLUDE: 


fOur complete list of 
software is too long to 
publish and changes by the hour 
but here are a few examples to 
whet your appetite. 



CP/M 80 CP/M 86 MS-DOS 

and IBM PC Software 


SOURCES INCLUDE: 


; We hold stocks of most 
software manufacturers 
including: 

MICROPRO 
MICROSOFT 
DIGITAL RESEARCH 
SORCIM 
IUS 

ASHTON TATE 


Software can be made 
available in 8 BIT or 16 
BIT formats to suit most micro- 
computers currently on the 
market including: 

Superbrain 
North Star Horizon 
North Star Advantage 
Columbia PC- IBM PC 
Televideo-Apple 
CP/M 8" -Rair-Sirius 


WORDSTAR 

PL/l-80 

BASIC-80 

FORTRAN-80 
SUPERCALC 
EASYFILER 
dBASE II 


MICROPRO'S 
comprehensive word 
processing system, 
DIGITAL s PL^I 
Compiler, 

MICROSOFT'S popular 
and powerful basic 
Interpreter. There is a 
Compiler too. 

Fortran Compiler to 
ANSI X3.91966 except 
COMPLETE data, 
SORClM's spread 
sheet and modelling 
system. 

Data Recording 
System for the IBM PC 
from IUS. 

Relational Database 
Management from 
Ashton Tate. 





RING THE SOFTLINE Grantham(0476) 860171 


All products are supplied complete with full originator's documentation. 
Please send large s.a.e. for full details. 

TRADE ENQUIRIES WELCOME. 



Soft option 

—SOFTWARE -CENTRE — 

The Soft Option (UK) Ltd. Home Farm House Colsterworth 
Grantham Lincolnshire NG33 5HZ Tel: Grantham (0476) 860171 


1 Circle No, 190 

153 


PRACTICAL COMPUTING October 1983 








260 C ALL 11 DBF CHAR' ME, 255,255, 255,255, 126 , 126,126,253 

270 CALL '* DHFCHAR ",13, 2SS , 254 , 252 , 0 , 0 , 0 , 0 , 0 

280 CALL" DEF C RAF? ,14, 253 , 1 27 ,63,0,0, 0 , 0 , 0 

290 C ALL " DEF CHAR '',15, 235 , 255 , 255 ,0,0,0, 0 , 0 

300 CALL " DEFCHAR" ,16,0,0,31,6,1,0,0,0 

3 1 0 CALL " DEFCHAR ",17,0,0,255,0,255,96,96,24 0 

320 CALL " DEFCHAR " , 18,0, 0 , 235 , 6 , 240 , 97 ,97 1 243 

330 CALL- DEFCHAR 1 , 19 , 235 , 255 , 255 ,255 , 255 , 255 , 255 , 255 

340 CALL "DCF CHAR 11 ,20,85,170, 170,235,255,253,255,255 

350 SH® = CHRJ U >+CHR*(2> *CHfU- ( 2) +CHR* (2>+CHR* f3> 

360 HE*^CHR$ (4>+CBR*(3> 

370 OTi-CHR* *6 ) +CHR* f 7 ) 

300 □M*^LHfti(SJ+CHR^ (9) 

390 OH* =CHR* <161 + CHR* 1 1 7 i -+CHR* ( 1 8 > +CHR* 1 1 0) ■+CHRJ <11.. 
400 GB*=LHR* 111) + CHR* ( 12) 4CHR* ( 1 5 > + CHR* f 1 2? +CHRS (1^) 
4 1 0 LE*=CHR* U 9 > +CHR* 1 32 > ■+ CHR * < 1 9 > 

4 20 BS* =C HR* < 32 i + C HR* i 4 B ) +CHR * < 32 3 +C HR* ( 32 ) + CMR * ( 32 ) 
430 5E^CHR*<20) 

440 BL* a CHR* (19) 

450 riES=STR*<HE) 

460 H5*-STR*(HS) 

470 SC*— STR* (SO 
480 REH DRAW 

490 CALL" COLOUR 11 , 0 , 20 
500 CALL "COLOUR" , 1 , 100 


waiting ship. Do not try to land on t he oil 
rig it you already have survivors, as the 
overload will cause you to crash . 

Winds can come from the left or right in 
forces from weak to gale force. At higher 
skill levels they can become stronger. 

Because the computer has a read-ahead 
keyboard, if you keep hitting the direction 
you need to go in it will remember the 
sequence and carry it out. If you tap the 
Down key when landing, the buffer will 
remember Down and on take off you will 
crash. An auto repeat is incorporated into 
the game so the key need only be pressed 
once. 

The machine code called at 750 works as 
a Get statement, but does so slightly 
faster. 


Summary of listing. 

10—130 Set up computer 

140—470 Set user characters 
480— 730 Draw graphics 
740 — 840 Move 
850 — 970 Check position 
980 — 1100 Random wind 
1110 — 1230 Pick up survivors 
1240—1380 Crash into rig 
1390—1470 Land on ship with no 
survivors 

1480—1620 Land on ship with survivors 

1630—1750 Land in sea 

1760 — 1900 Flown too high 

1910—2160 Game over 

2170—2390 Instructions 

2400 — 2450 Lines cut out of main loop 

2460—2530 Machine code 

2540—2680 Skill level 


RESEARCH 

MACHINES 

REVIEW 


Helicopter rescue 


Helicopter rescue 


in this program by Steve Crick of Herne 
Bay, Kent you are the pilot of a helicopter 
which must land on an oil rig to pick up 
survivors and take them over to the 


SEA L1JL RIG RESCUE 
crick . Hay 783 
Bay Secondary School 
RML 4002 with level 2 
Re so 1-tit i on Graph ins 


SO 

90 

100 

110 

120 

130 

140 

150 

160 

170 

100 

190 

200 

210 

220 

230 

240 

250 


154 


PRACTICAL COMPUTING October 1983 


Open file: Research Machines 




5 1 Q P LOT 0 , 59. , " SC ORE " 

520 PLOT 27,59,"L IVES 1 ' 

530 PLOT 40 , 59 HI SCORE" 

540 IF FX^l THEN GOTO 370 
550 FX = 1 

560 PLOT 11 ,59,88* 

570 PLOT 38, 5 9, ME* 

500 PLOT 64,59,HS* 

590 CALL "FILL" ,0,1 80 , 320 , 200 , 2 
600 A=200j X=48 

610 Xl-6O;Yl=61iX2^0O;Y2^61 

620 FOR X=1 TO 50 STEP 6 

630 CALL " STFL QT “ , A , X , VARA DR ( LE* > , 1 

640 NEXT 

650 C ALL" 5 T PLOT" , A~B , X , VARADR (OPT ) ,3 
660 CALL" STPLOT " , A- 8 , X + 0 , VARADR fOH*> ,3 
670 CALL. H STPLOT " , A+ 1 6 , X 1 6 , VAR ADR (0M±) i 3 
680 CALL"STPLOT",A-wi0, X+24 ,VARADR<DT*> ,3 
690 FOR X=0 TO 320 STEP 8 
700 CALL " S TPLti T " , X , 0 , VARA D R < SET ) , 2 
710 NEXT 

720 CAL L " STPLO T 1 1 ,0,8, VARADR i 5H* 1 , 3 
730 CALL "STPLOT" , X I , Y 1 , VARADR (HE* ) , 3 
740 REN NOVE 

750 CALL&600Q 

760 If INT<RND( 1>*I5)<5 THEN GOSUB 9B0 
770 P=PEEK(£5FFF> 

7S0 IF P- >OTHENQ=P ELSE P=U 
790 IF F-bQA THEN YI-Y1-2 

800 IF P-&OB THEN Yl=Yl+2 

810 IF P-4'08 THEN XT 1-3 

□20 IF P=X:1S THEN XI -XI +3 

030 Xt^Xl+LW 
840 Xl-X1“RW 

050 IF XI <202 AMD Xl -190 AND YI=71 THEN FS-TaGOTQ 2400 
060 If XI 300 THEN X 1=0 
070 If X1<0 THEN XI =300 
S80 IF YKS THEN GOTO 1630 

090 If Xl<te AMD XI >6 AND Yl=ll THEN FG=2iG0T0 2400 

900 If Y 1 <70 AND XK222 AND XI 104 THEN 1240 

910 IF Y 1 > 1 70 THEN 1760 

920 CALL "STPLOT" , X2, Y2 T VARADR ( HE* ) , 0 

930 CALL 1 ' STPLOT" , XI ,Yl , VARADR (HE*) ,3 

940 CALL "STPLOT " ,216,01, VARADR < OT* > , 3 

950 CALL" STPLOT" , 216 , 73 , VARADR < DM* > ,3 

960 X2=X1:Y2-YI 

970 GOTO 750 

980 REN WIND 

990 PUT 12 

1000 W = 1 NT < RND ( 1 l+3> 

1010 S-INT<RNDU5*5> 

1020 IF S=Q THEN WI* = 4 , Weak ' 1 

1030 IF 5=1 THEN WI*="Mild" 

1040 IF S=2 THEN W I *=" Moderate" 

1050 IF 5=5 THEN W I t* "Strong " 

1060 IF 5-4 THEN WI*="Gait force" 

1070 IF W=0 THEN ?WI*i, " wind from the Ri ght " : RW^S* 1+SKtLW^O 

1000 IF W-l THEN 714 1 *j" wjnd Tram the Let t " : RW-O: LW=S+ i +SK 

1090 IF U|=2 THEN 7" Wind dropped" : LW=OJ RW°0 

1 1 00 RETURN 

1110 REM PICK UP 

1120 CALL "STPLOT" , X2,Y2, VARADR (HL$) ,0 
1130 CALL "STPLOT", XI , Yl , VARADR (HE*) ,3 
1140 PUT 12 

1150 SU*lNT(RNO<iJ * 01+10 

1160 7 "You have succesful 1 y landed" 

1170 ?"and picked tip " 5 SU" survivers" 

1100 FL c 1 

1 1 90 FORT = 1TD2000J NEXTT 
1200 GOGUB 990 
1210 P“St08;0=*iDP 

1 220 CALL ■' STPLOT " , X l , Y 1 , VARADR (HE*) , Q 

1230 GOTO 740 

1240 REM CRASH 1 

1230 PUT 12 

1260 ? ,l Yo-u have crashed into the Oilrig" 

1270 IF FL =1 THEN ^"killing all of your survwers" 

1280 ME=ME -1 

1290 FGRT=1 TQ2O00: NEXTT 
1300 F C =0 
1310 PUT 12 

1320 IF ME-0 THEN 1910 
1330 ME* —SIR* (HE ) 

1340 PLOT 38, 59, ME* 

1350 X t“60 e Y 1 "6 1 
1360 P-^tOBi 0=feOB 

1370 CALL "STPLOT" ,X2,Y2, VARADR < HE*) ,0 
1300 GOT 0480 

1390 REM LAND WITHOUT 

1400 CALL "STPLOT ■' , X2 , Y2 , VAR ADR £ HE*) , 0 
1 410 CALL "STPLOT 11 , X 1 , Y 1 , VARADR < HE* ) , 3 
1420 PUT 12 

1430 ^"Why land without any survi vers?" 

1440 FORT- 1 TO 1000? NEXTT 
1450 PfciOBtOs&OB 

1460 CALL" STPLOT", XI ,Yl , VARADR ( HE* ) ,0 
1470 RETURN 

1400 REM LAND WITH 

1490 PUT 12 

1 500 CALL" ST F'LOT " , X2 , Y2 , VARADR { HE* > , 0 
1510 CALL "STPLOT" , XI,Yl , VARADR ( HE* 1 ,3 
1520 “'"Well done you have scored " (SU*lO 
1530 SC=SCt tSU*10) 

1540 8 T-ST+SU 
1550 SC*=5TR* (50 
1560 PLOT 11 , 59, SC* 

1570 FL=0 

15B0 F0RT=1 T 02000: NEX FT 
1590 P-bOBi'OF&QB 


1600 
1610 
1 620 
1030 
1 640 
1650 
166 V 
1670 
1600 
1690 
1700 
1710 
1720 
1 730 
1740 

1 750 
1760 
1770 
17 BO 

17tu 

1000 

1010 

1020 

1030 

1040 

1050 

1860 

1B70 

1880 

1890 

1900 

19)0 

1920 

1930 

1940 

1950 

1960 

1970 

1900 

1990 

2000 

2010 

2020 

2030 

2040 

2050 

2060 

2070 

2080 

2090 

2100 

2110 

7120 

2130 

2140 

2150 

2100 

2170 

2 ISO 
2190 
2200 
2210 
2220 
2230 
2240 
2250 
2260 
2270 
2280 
2290 
2300 
2310 
2320 
2330 
2340 
2350 
2360 
2370 
23S0 
2390 
2400 
2410 
2420 
24 30 
2440 
2450 
2460 
24 70 
2400 
2490 
2500 
2510 
2520 
2530 

2540 
2550 
2560 
2570 
2580 
2590 
2600 
2010 
2620 
26 SO 
264 V 
2650 
2001') 
26/0 
2680 


CALL " STF'LOT" , X 1 , Y 1 , VARADR t HE*) , 0 
A*-= "A" : B*- "A" 

GOTO 750 

REM SEA 

PUT 1 2 ij 

7"Yau have crashed into the sea" 

IF FL-1 THEN r < s,, fci.II ing all of your survavers" 

ME^ME-1 

FL=0 

X 1-00 : Y 1=61 

FORT- I TO I 000: NEXTT 

PUT 12 

IF ME=0 THEN 1910 
ME*=STR4 (ME! 

PLOT 38 , 59 , ME* 

GOTO 740 

REM I 00 HT8H 

PUT 12 

? " You have flpwn too high" 

It ihLW kalian^ all of y Qtir survivers’ 

ME=ME- 1 
X 1 ==60 : Y 1 - 6 1 
FL=0 

FOR X - 1 TO2000 : N E X T X 
IF m=0 THEN 191 O' 

ME*=STR* (ME) 

PLOT 38,59 ,ME* 

CALL " STPLOT" , X2 , Y2 , VARADR i HE* ) , 0 
PUT 12 
P=StO0: b=SjOB 
GOTO 900 

REM END 

call " STPLOT " ,X 2, Y2i VARADR ( HE * ) , Q 

PUT 12 

?"You have sent th^ rest tH " 

7" the crew to a watery grave" 

?"You saved " ; ST| "tnen. " 

IP SOHS THEN HS"SC 
HS*=STRi (HS> 

PLOT 64,59, HS* 

SC=0 
ST=0 
SU=0 
f X=0 
A*= " '■ 

" 

ME=3 

ME*=STR*(N£) 

SC*— STR* (SC) 

FL=0' 

F DRT= 1 T03000 : NEXTT 
PUT 12 

? ,L Do you want another go? (Y/NS 11 
CT-GET* l ) 

IF C*= " Y " OR C*-"y" THEN GOSUB 2540SSCT04BO 

DR C*-"n" THEN CALL u CLEAR" ; TEXT: END 


IF C*="N" 
GOTO 2130 
REM 
TEXT 
PUT 31 


INSTRUCTIONS 


North Sea Oil Rag Rescue 11 
Steve ~CrTck~. May/ 33" 




Instructi ons" 


"‘^"Due to a fault in the Oil Rig's legs" 
?"it is in danger of collapsing. You are" 
?"the pilot of the helicopter that is" 
^"trying to save the workers. To make" 
^"things worm? there are unpredictable" 

?" winds in the north sea, making your 1 ' 
7"landings d a f f i rul t . " 

7:7" You use the ARROW keys to move" 
Any other key to stop" 


Any key to play" 


?: ?" 

A-GET < > 

GOSUB 2540 
PUT 12 
RETURN 

REM CUT DOWN 

IF FL=0 AND FG= 1 THEN FG=0i.G0TG 1110 
IP FL=T AND FG- 1 THEN FG=0: GOTO 1240 
Tf FL— 0 AND FG=2 THEN FG-0; GOSUB 1390 
IF FL=1 AND F8=2 THEN FG^O;GOTO 1480 
GOTO 750 

REM MACHINE CODE 

POKE £6000,^7 

POKE 5:6001, ¥<02 

POKE Ss6002 , &32 

POKE ^6003 , &FF 

POKE fj. 6 004 , Zf 5F 

POKE ^6OOfe,0C9 

RETURN 

REM Sk I LL 

CALL" RESOLUT ION" ,0,2 
TEXT 
PUT 31 

?" Input Your 5k l 1 3 Level:-" 


7-O^EBsy 
7:7" t "Hard " 

' J : ? " 2-' V er y Hard" 

7: INPUT "Lev el ,3K 

IF SL O 0F< SK >2 THEN 2570 

7:^' "Any key to play' 1 

car^GET* n 

PUt 12 » GRAPH 
RETURN 


E3 


PRACTICAL COMPUTING October 1983 


155 



'Open file: Newbrain! 



General-purpose graph 

the first program is a general-purpose line 
graph program developed by Robert 
Lewsley, designed to take the tedium out of 
drawing graphs from measurements he 
takes in the course of his work. Three 
options are available. You may input from 
keyboard or tape, or input from keyboard 
while simultaneously copying the data to 
tape. The program allows you to specify the 
titles, ranges and scale positions for both 
the x- and y-axes. Then you may input the x 
and y co-ordinates. 

The program plots the graph as each set 
of co-ordinates is input, checking that the x 
value is greater than at the previous point. 
You can make multiple plots by specifying 
x and y values of zero to move the current 
position back to the start. Lines 2700 to 
3160 display full instructions for using the 
program. 


General-purpose graph. 


1000 hem 

1010 REM - general purpose graph program 
1020 REM - copyright R. Lews ley 1983 
1030 REM 

1050 

1060 DIM BREAK SOTO 3210 
1070 

1080 REM !»###**********+#*#**»###****# 
1090 

1100 e*=“ Invalid input - try again 1 ' 

1110 eZ^'Text too long - limit - 20 cha 


1120 

1130 

1140 

1150 

1160 


1170 

UBO 

1190 

1200 

1210 

1220 

1230 

1240 


1250 

1260 

1270 

1280 


CLOSER: OPENKO, 4, "200 11 iQOBUB 2700 
CLOSE# 129 
PUT 31 

PRINT "Enter processing apt ion (K8* 
KSiTI) " JLINPUT “)po* 

IF po*= "KB" OR pc*= ,h kb" OR po*®"KS" 
DR po**"ks" OR pa*="T l" OR po*="t 1 
" THEM 1180 

PRINT "Invalid processing option - 
try again" fPUT 12:GOTO 1150 
PUT 3i 

IF po*='W OR po*- ,l ktj“ THEN po=lfD 
DTO 1330 

IF po*~ "KS" OR 00 *=" ks" THEN po*2; 
GOTO 1280 

REM - tape input 

po=3s PRINT "Load’ input tape at corr 
ect point. " a PRINT "Press play then 
press newline when ready" !L INPUT x* 
:QPENIN£2, 1, “graph, data" iGOTO 1330 

REM - keyboard input plus save 

PRINT "Load new tape at start point 
, and presa N JPRINT 11 record/play. fl :P 
PINT “Then press newline when ready 
■ n JLINPUT «*?0PEN0UT#2. 1, "graph, dat 
a": GOTO 1330 


open graphics screen 
and draw skeleton 


1300 REM 
1310 REM 
1320 

1330 PUT 3iiOPENfl29, 11, "w200" t plot rng fl 
0, 10) T pia (0, 0) , wve (0, 9. 9) 

1340 p I otdeg, t by f ~90) T mby <9. 9 ) , t by f “90 ) 

1 350 p 1 ot mby (9. 9 > , t bv (-90 ) , mby < 9. 9 ) 

1360 

1370 IF po=3 THEN LINPUT£2, h* JGOTO 1490 

1380 

1390 

1400 REM - begin getting titles 

1410 REM and ranges 

1420 

1430 PRINT "Please enter title for graph 


1440 

1450 

1460 

1470 

1480 

1490 

1500 

1510 

1520 

1530 

1540 

1550 

1560 

1570 

1500 

1590 

1600 

1610 

1620 

1630 

1640 

1650 

1660 

1670 

1680 

1690 

1700 

1710 

1720 

1730 

1740 

1750 

1760 

1770 

1780 

1790 

1000 

1810 

1820 

1830 

1840 

1850 

I860 

1870 

1880 

1890 

1900 

1910 

1920 

1930 

1940 

1950 

1960 

1970 

1980 

1990 

2000 

2010 

2020 

2030 

2040 

2050 

2060 

2070 

2080 

2090 

2100 

2110 

2120 

2130 

2140 

2150 

2160 

2170 

2100 

2190 

2200 

2210 

2220 

2230 

2240 


LINPUT {ӣ ") h* 

IF LENHh*) < 2> THEN 1490 
PUT 31 J PRINT e2* 

GOTO 1440 

plot rng f 100 T 100) 

TF LEN<**)=0 THEN h*=" 

IF po-2 THEN PRINTS, X* 
x=flQ0~LEN<x*)*3)/2“3iIF x <0 THEN h 
= 1 

plot pla f x t 94) , x* 
pi otpla £0 t 0) 

PUT 31 

IF pn=3 THEN INPUTJC2, xl, Hh, yl, yMGO 
TO 1750 


ON ERROR GOTO 1630 

PRINT "Enter low and high values fo 

r X fnn, mi) " 

INPUT xl, xh 
GOTO 1640 

ON ERROR GOTO 0: PRINT e*:PUT 12IRES 
□ME 1590 

IF xb-xl > 0 THEN 1660 
PRINT e*:PUT 12J GOTO 1590 
PUT 31 

ON ERROR GOTO 1710 

PRINT “Enter low and high value* fo 
r V Cnn, tin) " 

INPUT yl,yh 
GOTO 1720 

ON ERROR GOTO Qi PRINT e*:PUT 12eRES 
UME 1670 

IF yh-yt ) 0 THEN 1740 
PRINT e*: PUT 12SG0T0 1670 
ON ERROR GOTO 0 
PUT 31 

IF po-2 THEN PRINTS, xi, xh,y I, yh 
IF po=3 THEN INPUTC2, X* JGOTO 1840 
°RINT "Enter title for X axis“ 

lINPUT h* 

IF LEN<h*) <21 THEN 1030 

PRINT & 2* 

PUT 12! GOTO 1700 
IE LENix*)“0 THEN h*=t"X axis" 

«■= < 100 -LEW ( k* ) *3 ) /2-3 J I F x <0 THEN h 
■1 

pi otpla f x, 01 ) T x* 

PUT 31 

rF pp-2 THEN PRINT#2, x* 

IF po~3 THEN INPUTS, MiiGOTO 1940 
PRINT “Enter title for V awis" 
LINPUT x* 

IF LEN< x* ) <21 THEN 1940 
PRINT e* 

PUT 12:GDT0 1090 
IF LEN<x*)=0 THEN x**"Y axis" 

IF po=2 THEN PRINTE2,** 

h*< 100-LENtx*)#3)/2-3£lF m < 0 THEN x 

*1 

X“100-n 

FOR i=l TO LEN<n*> 
plotplad, h) , MID****, i T 11 
h^x-4 
NEXT i 

P lateen ( 5, 7 ) , p 1 a 1 0, 0) 
n*=STR*<xn : h=LEN<x*)-] 
h*=LEFT*<h*,h) 
h=LENLh*) -1 
k*=RIGHT*<x*, h) 
plotpla <-3, -6) , h* 
x*-STR*( Hh) J h=LEN<k*)~ 1 
xS=LEFT*<w*, h) 
x=LEN(x*)-l 
x*=*RIGHT*U*,m) 
h= 95- < x*4) 
plot plain, -6 ) , m* 
m*“STR*< yh) J k-LENTk*) -1 
«*”LEFT* (k*, m) 

X“LEN<x*)-l 
x*-RIGHT*<x*, h> 
plotpla (-3, 87) , x * 
h*“STR* < y n E m°L£N ( x* ) - 1 
h*=-LEFT*{k*, m) 

X“LEN(k*)- 1 
w*=RIGHT* { x*, h) 
plotpla<-3, -2), w* 
x=xh-xl *y=yh^yl 


2250 pi at rng ( x, y 1 T cen< 0, 0) 

2260 xp“0-H/10Jyp-0-y/10 

2270 PUT 31 

2280 FOR i*l TO 10 

2290 Hp=Kp+x710ipJetpla<xp T 0>, mvefxp, yfl 
00) 

2300 yp-yp+y/10:pltjtpla(0, yp) , mve< x7100 d 

yp) 

2310 NEXT i 

2320 plotpla (0, 0) i mp=h1-1 
2330 

2340 PUT 31 ■ 

2350 IF po O 3 THEN 2460 
2360 

2370 HEM *• draw graph from tape data 
2380 

2390 INPUTE2, ** 

2400 IF AGO (x* 1=4 THEN PUT 31 : PRINT "D is 
play complete “ press npwl ine” i PR IN 
T "to terminate run. LINPUT x*:$T0 
P 

2410 xp= VAL < k* > i I NPUTJE2, x* : y p-VflL ( x* ) f GO 
TO 2510 

2420 

2430 REM - begin drawing using keyboard 

2440 REM i nput 

2450 

2460 ON ERROR GOTO 2500 

2470 PRINT "Enter X and Y coordinates <n 
n, nn) " 

2480 TNPUT xp T yp 
2490 GOTO 2510 

2500 ON ERROR GOTO 0: PRINT e*:PUT 12 f 12: 

RESUME 2460 
2510 ON ERROR GOTO 0 
2520 IF hp < 10 OR yp<>0 THEN 2570 
2530 pi atpla (0, 0) - ko=M 1^1 ! IF po-1 THEN P 
UT 12 JGOTO 2460 
2540 IF po=3 THEN 2390 

2550 «*=STR* < xp) : PRINTK2, x*i x*=STR* <yp> J 
PRTNTC2, M* 

2560 GOTO 2340 

2570 IF po<=3 THEN 2630 

2580 IF xp)=xl AND hp<=xH THEN 2600 

2590 PRINT e*JPUT 12 i GOTO 2460 

2600 IF yp <yl OR yp) yh THEN 2590 

2610 IF x p < — x o THEN 2590 

2620 IF po-2 THEN m*=STR* f xp) : PRINTC2, x* 

J k*=STR* < y p ) J PRI NT£2 , m * 

2630 xo“Xp 

'2640 Xp-Hp-wl Jyp=yp-yl 
2650 plotmve txp, yp) 

2660 GOTO 2340 
2670 

2600 REM - user instruction routine 
2690 

2700 PUT 31 

2710 x*-"General Purpose Graph Program" 
2720 PRINT TAD (20 -LEN<k*) 72) J x* 

2730 x*="(c) Copyright R. Lewsley 1983 11 
2740 PRINT TABf20-LENfx*)/2 ) jh* 

2750 PUT 10 

2760 PRINT "Do you require instructions 
y/n 11 ; s LINPUT x* 

2770 IF x*= "n" DR x*="N" THEN 3170 
2780 IF x*=“y“ OR x*="¥" THEN PUT 31: GOT 
0 2800 

2790 PUT 12IG0T0 2710 

2000 PRINT "This program will draw a gra 
ph using" 

2310 PRINT "either keyboard or tape inpu 
t data. " 

2020 PUT 10! PRINT "If keyboard input is 
selected “ 

2830 PRINT "the program will initially r 
equest a" 

2840 PRINT "title for the graph, then ask 
for the" 

2850 PRINT “low and high range values of 
t he" 

2860 PRINT n X ^horizontal) and Y tvertlc 
all axes." 

2870 PUT 10 

2880 PRINT "It will then recjuest head i no 
s and scale" 

2890 PRINT "mark values for these two ax 
es. ,f 

2900 PUT 10 

2910 PRINT "At this stage a skeleton lay 
out " 

2920 PRINT "will be drawn and you will b 
t> asked" 

2930 PRINT “to begin entering the X and 
Y values. h JPUT 10, 10, 10 
2940 LINPUT ("press newline to continue" 

) x*! PUT 31 

2950 PRINT "Plotting will be done immedi 
ately and" 

2960 PRINT "each new set of X.Y values w 
ill be" 

2970 PRINT "checked to ensure that X is 
greater" 

2980 PRINT “than its previous value." 
2990 PUT 10 

{continued on page 158 ) 


156 


PRACTICAL COMPUTING October 1983 




Mlcrollne 84 

Highest performance and reliability place these 
printers on top of the Microline printer series. The 
printhead is designed for over 200 Million character 
printing. 

Printing speed is 200 cps in data processing mode 
and 50 cps is achieved in correspondence quality 
mode. Character types are user defined. 

A choice of character sets is permanently stored in the 
printer's EPROMs. 

Additional memory space is provided to store one's 
own specific character set. This happens by down- 
loading the specific character set from one's computer 
to the printer before the printout begins. 

The carriage width oft 3 6 characters allows the use of 
A4 paper in portrait or landscape formats, lrom an 
optionally available single sheet feeder. 

The interface parts allow for parallel or serial data 
transfer - buffered or unbuffered from most popular 
desk top computers and widely used PCs. 


MICROLIKE - more than 

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• Circle No. 247 

157 


PRACTICAL COMPUTING October 1983 



Open file: Newbrain 



(continued from page 156} 

5000 PH I NT "Multiple pi atm may he rtiade b 
y entering" 

3Q1Q PRINT "zero far both X and V T this 
will move" 

3020 PRINT “the current plotting posit i o 
n back to" 

3030 PRINT ‘the start point," 

3040 PUT 10, 10, 10 

3050 PRINT “To terminate the prog rant pre 
ss the" 

30&0 PRINT “stop key followed by newline 

VI 

3070 PUT 10, JOJLINPUT t "press newline to 
proceed ”) k* 

30S0 PUT 31 

3090 PRINT "Three processing options are 
available, " 

3100 PUT 10 -PRINT "KB - meaning keyboard 
input for 11 

3110 PRINT M immediate display only, 

III L 

3120 PUT 10: PRINT "KS - meaning keyboard 
input for display" 

3130 PRINT " plus save to tape for 1 
ater use, " 

3140 PUT 101 PRINT "TI - meaning display 
previously saved" 

3 ISO PRINT N data from tape input, " 
3160 PUT 10, 10 ? L INPUT ("press newline to 
proceed “ )n% 

3170 PUT 31 m - RETURN 
3180 

3190 REN CLOSEDOWN ROUTINE 
3200 

3210 ON BREAK GOTO OUF po~2 THEN 3240 
3220 CL0SEC2 * CLOSED 1 29 
3230 PUT 31 i PRINT ,p READY M i END 
3240 PRINTS, CNR* 14) 

3250 GOTO 3220 


Format 40 

This program by Robert Lewsley prints 
program listings in the 40-column format 
preferred by this magazine, I certainly 
found it useful in preparing some of the 
listings. Lines 2140 to 2170 describe how to 
store a program on tape prior to printing it. 
I found it better to specify a file name when 
storing my programs using the commands: 

OPEN QUT£1,1/ l progrm name 1 ’ in place 

of the command on line 2140 

Once your program is stored, Format 40 
just has to be loaded and run to list it out. 
Line 2310 outputs some special initial- 
isation characters for the Oki Microline 82a 
printer, it may have to be changed for your 
own printer. 

Multiple screens 

One of the most powerful features of the 
Newbrain is its ability to open a number of 
streams for one device. In particular, you 
can set up multiple screen displays which 
can be switched between at will. 

Edward Thomas from Clapton, London 
E5, sent in two programs which 
demonstrate this very well and also 


illustrate some of the features of the 
Newbrain high-resolution graphics. The 
first program. Bounce, opens two display 
streams on ports 1 and 2, and two linked 
graphics streams. It then draws a circle on 
each graphics stream and fills them in. 
Finally, the program goes into a loop where 
each stream is displayed in turn with a time 
delay between each display. The resulting 
effect is of a bouncing ball. 

The second program is slightly more 
complex, using three streams. When run, 
Rotate will draw a four-pointed petal 
which, when completed, will start spinning 
anti-clockwise. Graphics use rather a lot of 
memory so three screens is the limit for this 
type of display with the standard system, 
and fully animated cartoons are out of the 
question. 

Many useful facilities can still be 
provided with text displays. For example, 
help information and option menus could 
be stored on separate streams from the 
main display, to be called up as required. It 
is also possible to plot to one stream while 
the other stream is being displayed. 
Provided it does not take too long to plot 
the changes between displays, it should be 
possible to perform limited animation, (TJ 


158 


PRACTICAL COMPUTING October 1983 


DTAIfTECTSO 





printer. 


DIAL-TEXT SO is a simple to use 
electro Flic typewriter (ET) to electronic 
typewriter communications device, Ilis 
plug compatible with the OCTET 12 1 
and HERMIT 21 interfaces designed by 
Duplex and can also be used with any 
RS232 device such as a microcomputer 

simple to install 

Installation is easy and no special wiring 
is required - communication is achieved 
by simple cable connection oi through any 
acoustic coupler. For instance, the user can 
simply place the DIAL-TEXT 50 unit and 
acoustic coupler between an OCTET 121 or 
HERMIT 21 typewriter and a standard 
telephone handset for transmission of ERROR 
FREE letters and documents (or telex 
messages) to a remote DIAL -TEXT 50 unit and 
acoustic coupler; nationally or internationally, 

Typical application 

The DIAL-TEXT 50 unit is ideal for remote offices 
which would like to use the main office telex 
facilities; Text can be prepared at the remote office and 
transmitted to the mam office to cut telex paper tape for 
forward transmission. Incoming telexes for the remote 
office would receive messages in the reverse 
manner. 

Special Dial-Text 50 features & benefits 

1. 16,000 CHARACTER MEMORY. Retains contents when 
power is off. 


2 . ERROR free messages 
through use of automatic 
ERROR DETECTION and 
CORRECTION facility. 

3. TRANSMISSION SPEED 
approx, 5 times faster than a 
standard telex machine, 
providing the FULL range of 
typewriter characters 
and symbols, 
upper-case and lower- 
case. 

4. MENU DRIVEN 
through a 16 character 
display 

5. OPERATORS 
CONTROL PANEL for 
message viewing and 
deletion, 

6. INCOMING/OUTGOING 
messages automatically differentiated 
by special character. 

7, ABILITY TO PRINT (retrieve) messages 
from the DIAL-TEXT 50 unit, at any time. 

8 ABILITY TO STORE messages onto a standard tape 
cassette unit. (Ask for l he OCTET or HERMIT TI unit) 

9. CONVENIENT/CONFIDENTIAL MESSAGE HANDLING, 
te use own secretary as operator, 

10. PO iVTABL E I igh l weight stand-alo ne unit wi th o wn 240v 
power supply which can be shared within the office. 

11. DIAL-TEXT 50 allows local text processing without the 
need to transmit messages. 

12. COST of transmission limited to normal telephone rates. 

13. MESSAGE SCRAMBLER facility, (optional). 




Midlands/North— 2 Lei re Lane, D unton Bassett, Nr. Lutterworth, Leicestershire LEI 7 5JP, Tel: 0455 209131 


South— 52 High Street, Stock, Essex CM49BW. Tel 0277 841011 


• Circle No. 191 


PRACTICAL COMPUTING October 1983 


159 


SINCLAIR 
LINE-DP 



User-defined 1/ O routines 

a LITTLE PIECE of detective work has 
enabled Larry Carasco of Dollis Hill to 
produce the program which will allow the 
Spectrum stream facilities to be utilised. 
The streams will be used with the Sinclair 
Microdrives and networking board. 

Anybody who already has some form of 
I/O device attached to their Spectrum 
might be able to put this program to use im- 
mediately. A channel consists of five bytes 
of code which define which routines are be- 
ing used for I/O. The format is: 

• Address of output routine, 

• Address of input routine, 

• File name. 

The file name consists of a single 
character — of which more later. The 
Spectrum has a series of 19 streams which 
indicate where the channels are situated, of 
which 16 are available to the user. A stream 
is simply a 16-bit pointer to a channel. The 
address of the first channel is in 
Chans, 23631. 

A stream which has been opened 
contains a pointer, which is 0 if the stream 
is closed. The channel to which it points is 
at 

CHANS + pointer - 1. 

Thus if Chans is 23734 and the pointer is 6 
then the channel is at address 23739. 

The Spectrum manual states that Strms is 
at 23568, the address of the first stream 
pointer. However, the streams at 23568, 
23570 and 23572 are not available to the 
user so the address of the First user stream, 
called Stream 0, is 23574. The address of 
any given stream is at 

23574 + 2 x stream number 

where the stream is any number between 0 
and 15. The contents of this address plus 
Chans minus 1 gives the channel its uses. 
Table 1 shows the stream addresses, their 
pointers and the channel data they point to. 

Streams 0 to 3 are normally used by the 
Spectrum for display and input. Streams 0 
and 1 point to the same channel and are 
used to write to screen lines 22 and 23 and 
also to read the keyboard. Stream 2 is used 
by the Print and List statements to output 
to lines 0 to 21. Stream 3 is used by the 
printer; LPrint and LList use this stream. 

Examining the channels which these 


streams point to clarifies the I/O structure. 
Table 2 shows the channels which the 
Spectrum sets up on default. The channel 
data is situated at Chans to Chans + 19. 

The subroutine at 2548 is a conventional 
output routine, and 4264 is an input routine 
which returns characters entered from the 
keyboard. The routine at 3969 probably 
requires extra hardware to function as 
intended. The routine at 5572 causes error J 
to occur: you may not input from this 
device. The file name is a mnemonic for the 
channel’s I/O port: 

K = keyboard and lines 22,23 
S= screen, lines 0 to 21 
R = RS-232 (?) 

P= Printer 

No other file name is valid, and only K, S 
and P may be specified by the user. 

Although three channels use the same 
output routine, Basic sets various flags to 
indicate which channel is being serviced. 
The file name decides which flags are set. 
This means, for instance, that when using 
Channel P the output is not echoed to the 
screen. Using this method of streams and 
channels reduces the amount of memory 
required to handle many different I/O 
routines. 

All the streams using a particular channel 
have their pointers set to the same value, 
and all 16 streams could use the same 
channel — though it would be rather 
pointless. Five bytes of data would then 
service the entire I/O network. The address 
of the channel currently in use is held in 
Curchl, 23633. 

A specific stream can be selected by 
inserting a # sign, CHR$ 35, and a stream 
number. For example. 

PRINT #3; “Hello!” 

will output to the printer. Using table 2 to 
help establish what effect the different 
channels have, try out different streams for 
this example. Only streams 0 to 3 are valid 
at present. 

Inkey $, Print and Input may all use 
stream values. Now try 

LPRINT tt 2; “HI!” 

A command which normally writes to the 


printer has been told to use Stream 2, which 
in turn has directed it to Channel S. 

All I/O statements, except Verify, Save 
and Merge, always use streams but because 
they use default values when one has not 
been specified this is, perhaps, not 
apparent. Print defaults to Stream 2, LPrint 
to Stream 3 and so on. When you specify a 
particular stream you are directing the I/O 
of that statement to a chosen channel. 

Contrary to the insistence of the manual, 
the Open and Close statements can be used 
without extra hardware, as you may have 
already discovered. When you use them 
you are actually defining which channel 
you wish that stream to use. The format is: 

OPEN # stream number, file name 
The valid file names are K,S and P. 

Try entering 

PRINT #5:“lllegal” 

You should try to get an Error 0 report, but 
if you first enter 

PRINT #5, “S” 

the text should appear on the screen. What 
you have done is opened Stream 5 and 
instructed it to use Channel S. Any stream 
number between 4 and 15 will work. 

Streams 0 to 3 will also work, but you 
will be altering the normal system I/O 
configuration. You should always take care 
when altering them or you may lock 
yourself out of the system. If you want a 
demonstration, 

OPEN #3, “S” 

is fairly safe and will cause printer output to 
be rerouted to the screen. 

The Close statement naturally enough 
closes down the chosen stream. For streams 
4 to 15 it resets their pointers to 0, 
indicating that the stream is disconnected 
— see table 1 . Closing streams 0 to 3 results 


Channel 

Output 

Input 

File 


address 

address 

name 

0 

2548 

4264 

K 

1 

2548 

5572 

S 

2 

3969 

5572 

R 

3 

2548 

5572 

P 

Table 2: The Spectrum’s four channels. 


Stream 

Address 

Pointer value 

Channel address 

0 

23574 

0001 

23734 

1 

23576 

0001 

23734 

2 

23578 

0006 

23739 

3 

23580 

0016 

23749 

4 

23582 

0000 

CLOSED 

5 

23584 

0000 

CLOSED 

6 

23586 

0000 

CLOSED 

7 

23588 

0000 

CLOSED 

8 

23590 

0000 

CLOSED 

9 

23592 

0000 

CLOSED 

10 

23594 

0000 

CLOSED 

11 

23596 

0000 

CLOSED 

12 

23598 

0000 

CLOSED 

13 

23600 

0000 

CLOSED 

14 

23602 

0000 

CLOSED 

15 23604 0000 

1. Breakdown of stream data, values in decimal. 

CLOSED 


160 


PRACTICAL COMPUTING October 1983 



Open file: Sinclair 


User-defined I/O routines. 

10 REfl 1B34^5S 

P0 POKE 5375S , 0 ; PORE 2375© .. 14- 
30 INPUT "Open stream no? M ; cn 
4.3 INPUT "Output routine add re 
ss? " ; ou t r , t , 

S3 INPUT “input routine a a a r s *■ 

s ? 11 i inf — „ _ _ _ 

6 & L ET c h = P L E K 2 S b3t+PtuK E 'P 

2^56 

^0 LET z-237t>i 

30 LET a ; LET X =OU t f i GO SUE 
|p 00 

3© let a=a+2: LET X=inr: 130 so 
B SS0 

is© poke a +s ± code f $ 

110 LET a =S3iS z4 - tlm 

120 LET x - 1 -FZ - C h : GO 5UB 

499 STOP 

500 POKE a * K - I NT C X /255 ) ESS& 

610 POKE a +1 , INT Lx /256> : RET UR 

N 


Input routine address: 5572 
File name: "S” 

Now try LList. Every character should 
appear as A: you have routed the printer 
stream through your own output channel 
which will only allow As to be printed. You 
could 

POKE USR “a” + 1 

with any other ASCII character code to 
output that character instead. If you try 
PRINT INKEYS #3 
you will get Error J . 

To erase the main program hut keep 
initialised streams enter the following: 

LET var = PEEK 23627 + PEEK 23628 x 
256 

LET a = var - 23771 

POKE 23769, a - INT (a/256) X 256 

POKE 23770, l NT (a/256) 

Delete line 20 and the program is deleted, 
save for line 0 which cannot be deleted 
because it contains the channel data. 

This program only sets up a new channel 
for a stream to use. You must define your 
own I/O routines to service the channel. 
These routines could be used for just about 


any peripheral you can attach to a 
Spectrum, be it a networking system, a 
Teletype or even another Spectrum. All you 
need to know is that the alternative register 
set should not be used, the output routine 
should output the value in the A register — 
preserving it, if possible — and the input 
routine should return with the Carry Hag 
set if a valid character has been received, 
reset if not. Unless the interrupt is disabled 
by your routine the routine is interruptible, 
so try to avoid any unorthodox stack 
handling. 

Smooth scroll 

a variable degree of scroll is provided by 
this routine for the Spectrum, written by 
Paul Maycock of Bristol, The program 
loads the machine-code routine in the Data 
statement and then saves it for future use as 
a subroutine in any Basic program. The 
routine itself when called will scroll, so to 
scroll one line would require a For-Next of 
8 . 

{ continued on page 163) 


\ values. Be careful when closing streams 
down: an unfortunate program bug crashes 
the system when you attempt to Close a 
stream which was never Opened. 

Even though you now know how the 
streams and channels operate constructing 
your own I/O routines is not as simple as it 
might be. At present you have only three 
channels you may use, K,S and P. Any 
other letter is discarded as an illegal file 
name. 

To get round this you must create your 
own channel by a back-door method. The 
program will create just such a channel. 

Line 20 allocates five bytes of memory for 
the channel data by setting up a dummy line 
0, The addresses of your new I/O routines 
are Poked into this dummy line. Finally 
you must give the channel a legal file name, 
otherwise the system will fail to recognise it 
as legal and might crash when you come to 
close down a stream. 

To allow easy access to the screen the 
channel can be called S, When you open a 
stream to Channel S using the conventional 
method it will still think you mean the 
original S channel. With the channel thus 
set up we simply Poke in the stream’s new 
pointer whose value is arrived at by: 
address of new channel — CHANS + L 
To initialise any other stream to this 
channel just use: 

LET cn = new stream number : GOTO 110 
If any of the variables has been altered, run 
the program again specifying the new 
stream. The other streams will remain 
intact. To test the program try the 
following: 

LET a = USR lf a": POKE a p 62: POKE 
a+ 1 r 65:POKE a -f 2,195 
POKE a 4- 3,244:PGKE a + 4,9 

Now run the program and answer the 
prompts as follows: 

Stream number: 3 
Output routine address: USR ‘a’ 1 

Smooth scroll. 

100 REM by P Maycock 18/ 1/83 
1 1 0 DAT A 33 , 0 , 65 , 17,0, 64 ,6,3, 19 

7.6.8.197.6.7. 197.1.32.0. 237. 176 
, 1,224,0,9,229,213,225,9,229,209 
, 225 ,193,16, 236 , 1 , 224 , 7 , 237 , 66 , 1 
, 32 , 0 , 237 ,176,1,32,0, 237 , 66 , 229 

120 DATA 209,1,0,1,9,193,16,209 
, 1 ,0,7,213,225,9,1,32,0,229,237, 

66 . 229 . 209 . 225 . 1 . 32 . 0 . 237 . 176 . 1 , 
0, 1,213,225,9, 193,16, 177,33,224, 

87 .1.0. 32 . 1 13.35.16.252.201 
130 INPUT "Start Address ?%s 
140 FOR f~0 TO 97 

150 READ a 
160 POKE s-Ff , a 
170 NEXT i 

190 SAVE "scroll mc"CODE s,98 
200 INPUT "Press ENTER to verif 
y"j LINE a$ 

210 VERIFY "scroll me "CODE 


Bridge hand. 

I 

iO DIM A<52> 

20 FOR 1=1 TO 52 . 

30 LET A(I) = INT (d-D/13) 

40 NEXT I 

50 FOR I F 52 TO 2 STEP 
60 LET T=INT(RND*I+i> 

70 LET R=Ad> 

80 LET A(I)=A(T) 

90 LET A <T) =R 
100 NEXT I 
110 FOR K = 0 TO 3 
120 PRINT "NORTHEAST SOUTHWEST 11 
CK*5+i TO K*5*5> 5 
140 FOR J= O TO 3 
150 PRINT 

160 FOR I = 1 TO 13 
170 IF A <J* 13+1) OK THEN GOTO 210 
180 LET R* = 11 11 + 11 234567890 J GK A 11 
d>^ ll SHDC u (Jf+l )* 11 11 

{ listing continued on page !63) 


161 


PRACTICAL COMPUTING October 1983 





It’s time to S-T-R-E-T-C-H your Micro! 


with new books and software from MCGraw-Hill 



□ Information Handling fortheZX Spectrum 

C.A. Street 

This book explains how fife handling programs are 
designed, used, developed, and written. Details of the 
accompanying software are given below. 

ISBN 07 084707 X £6.95 

□ Spectrum Information Handling Routines 

C.A. Street 

Contains thirty programs and program segments with 
machine code routines for sorting. Saves hours of 
keying! 

ISBN 07 084726 6 £6,95 inc VAT 




□ PROFILE 1 

C.A. Street 

A spreadsheet file handling system for the hobbyist or 
small business needing a cataloguing, mailing or stock 
control system. Handles both numeric and alphabetic 
information, selects, prints, processes, calculates and 
manipulates words and numbers. 

ISBN 07 084706 1 £9.95 inc VAtJ 




□ The Spectrum Workshop: Word 
Processing and Beyond 
Randle Hurley 

The Spectrum can be used as a word processor! The 
programs in this book are as comprehensive as a 
dedicated commercial package, and are fully 
described, line byline. 

ISBN 07 084704 5 £6.95 

□ Spectrum Interfacing and Projects 

G.D. Bishop 

This book shows how to use the Spectrum to control 
the outside world and contains many examples, 
programs and circuits, including a DAC, ADC and 
latch. Hardware kits are available for projects, 

ISBN 07 084702 9 £6.95 

□ Spectrum Interfacing Programs 

G.D. Bishop 

This support software provides ail the necessary 
programs to drive the projects in the above book 
ISBN 07 084709 6 £6.95 inc VAT 




□ ZX81/TS10G0 Programming 
for Young Programmers " 

Linda Hurley 

A book intended to teach children aged 9 upwards how 
to program in BASIC, through games and movements, 
calculated to hold a child's interest. 

ISBN 07 084595 6 £4.95 

0 ZX81 /TS1 000 Programs for Young 
Programmers 
Linda Hurley 

Consists of three games programs not included in the 
above book and provides many extensions and 
improvements in the book. 

ISBN 07 084700 2 £5.95 inc VAT j 




These books will be avai latole at alt good booksellers, bul in case of dSMiculiy you may order any 
of tho above books, by just ticking ihe titles you require: FIJI in your name end address, and send 
(his advert (or a copy of it) with your cheque or posial order (o: 

Marketing Services Department. McGraw-Hill Book Company (UK) Limited, FREEPOST. 
Maidenhead. Berkshire, SL6 2BU. 



L - Learn and Use Assembly Language on the 
ZX Spectrum 
Tony Woods 

This book provides a detailed step-by-step 
introduction to Assembly Language Programming. 

ISBN 07084705 3 £6.95 

□ ZX Spectrum Machine Code Assembler 

ACS 

A full-function machine code assembler which 
enables the Spectrum to l speak n Z80 Assembly 
Language. A must for arcade enthusiasts. 

ISBN 07 0847177 £7.95 inc VAT 

□ Invent and Wri^p Games for the ZX 
Spectrum 
Noel Williams 

This book teaches you how to write your own graphic 
and adventure games programs. See befow for 
accompanying software. 

ISBN 07 084719 3 £6,95 

□ Spectrum Adventures 

Noel Williams 

Three games are included along with additional 
programs not in the book. The programs are l [stable 
and can be examined and modified. 

ISBN 07 084720 7 £5.95 inc VAT 

□ Programming the Dragon for Games and 
Graphics 
Geoff Phillips 

Programming techniques in BASIC - including a stock 
control (freezer contents) program, an Adventure 
game, and Star Battle. See accompanying software. 
ISBN 07 084703 7 £5.95 

□ Dragon Games and Graphics 

Geoff Phillips 

All the major programs in the book - Breakout. Ciock. 
Freezer, Adventure, Cards and Star Battle, All in 
BASIC, can be listed, to save a lot of keying, 

ISBN 07 08471 5 £7.95 inc VAT 

□ Structured Programming: A First Course 
for Students and Hobbyists 
Peter Gosling 

The merits and techniques of structured programming 
are explained in this book, with examples of the way 
real-life programs are designed and written, 

ISBN 07 084701 0 £5.95 

□ Please send me further details about the above series . 





Name: _ 

Address: 


PRC 


• Circle No, 192 


162 


PRACTICAL COMPUTI NG October 1983 






Open file: Sinclair 


(continued from page 161 ) 

When ihe program is run it asks for the 
start address where the code is to be Poked. 
It can be anywhere in the free RAM but is 
most likely to be 32500 in a 16K Spectrum 
or 65200 in a 48K machine. To call the 
routine use Randomise User s, where s Is 
the value which you input when the 
program asks for the start address. 


Correlation coefficient 

A program for the 16K Spectrum by 
Michael Coombes of Caerleon, Gwent 
calculates the product-moment correlation 
coefficient of a set of data. It will be useful 
to anyone studying or using statistics. 
Instructions are included in the program. 


Side scroll 

an improvement to the routine by C D 
Henderson, published in the March issue, 
comes from M J V Moreton of Cambridge. 
He points out a number of faults in Mr 
Henderson’s routine: 

• Some of the scans in lines 16 to 24 are 
not scrolled. 

• The screen attributes are not scrolled. 

• Items which disappear from the screen 
reappear at the right-hand side Jin. 
higher. 

This routine does not attempt to wrap the 
screen around but it does avoid the faults of 
the earlier version. The routine may be 
called by 

LET variable = USR (32556) 
and may be relocated elsewhere in RAM. ! 


Side scroll. 

10 CLEAR 32555 

20 LET sum=0 

30 FOR n =32556 TO 32599 

40 READ at POKE n,a 

50 LET sum=sura+a 

60 NEXT n 

70 IF sum=2944 THEN STOP 
80 PRINT FLASH 1 5 ’’Error ’ * 1 
90 DATA 22,0,33,0,64 
100 DATA 1,32,0,30,192 
110 DATA 114,9,29,32,251 
120 DATA 58,141,92,30,24 
130 DATA 119,9,29,32,251 
140 DATA 33,1,64,17,0 
150 DATA 64,1,0,27,237 
160 DATA 176,18,33,255,87 
j 170 DATA 22,0,114,201 


Bridge hand 

If you enjoy bridge, this short program by 
P A Smith will help you to keep your 
bidding up to the mark. It is written for the 
unexpanded ZX-81 and could easily be 
expanded to print a series of hands. 


Bridge hand listing summary. 

Line 10 — Initialises array A(52)to represent Line 140 - Scans four suits. 

cards. Line 160 — Scans 13 cards per suit. 

Lines 20 to 40 — With 13 each of 0-3 to Line 170 — Checks if card belongs to hand. 

represent players, in arbitrary order. Line 180 to 190 — Creates strings RS for 
Lines 50 to 100 — Form random card. 

permutation. Line 200 — Prints card. 

Line 110 — Prints four hands. 


(continued from page 161 ) 

190 IF R$(2> = "O" THEN LET 
RfMl) . ="1“ 

200 PRINT R*; 

210 NEXT I 
220 NEXT J 
230 PRINT 
240 NEXT K 


Correlation coefficient. 

10 REM Product Moment 

Correlation Coefficient 
M. Coombes 1963 

12 PAPER O: BORDER O: CLS : IN 
K 7 

15 LET swmxx=Os LET sumyy=0: L 
ET sumx= 0 : LET sumy=Os LET sumxy 
=0 

20 INPUT "How many values of x 
? " ; nx 

30 BEEP .1,1 

35 DIM x (nx) : DIM y (nx) 

40 PRINT AT 15,0; “Please enter 
all the values of x,each fo 

1 lowed by ENTER. . . “ 

50 FOR f=l TO nx 
60 INPUT x (f > 

65 BEEP . 1,1 

67 LET sumx=SLtmx+x (f ) 

68 LET sumx x =sumx x + ( x ( f ) "*2 ) 

70 PRINT AT 19,0; ” 

"5 AT., 19,0; "x 
value ";f ; " = ";x (f ) 

80 NEXT f 
■ 90 CLS 


100 BEEP .4,10 

110 PRINT AT 15,0; "Please enter 
all the values of y,each fo 

11 owed by ENTER..." 

120 FOR f=l TO nx 
130 INPUT y (f > 

140 BEEP .1,1 

141 LET sumxy=sumxy+ (x (f ) *y (f ) ) 

1 42 LET sumy y=sumy y + ( y ( f ) -"-2 ) 

145 LET sumy=sumy+y (f ) 

150 PRINT AT 19,0;" 

" ; AT 19,0; "y 
value 11 ; f ; " = " ;y(f> 

160 NEXT f 
165 BEEP .4,10 

170 LET suffla=surax A 2 : LET sumb^s 
umy '-2 

200 REM ^Calculate Coefficent* 

2 1 0 LET ca= ( sumx y- < t sumx *sumy ) / 
nx ) ) / (SQR ( (sumxx- (suma/nx ) ) * (su 
myy— (sumb/nx ) ) ) ) 

300 REM *Print Answer* 

310 PRINT AT 9 , 0 ; "The product m 
ament correlation coefficient fo 
r your data is; " ' 

320 PRINT INK 5;co 
330 PRINT AT 15,0; INK 6 ; "Press 
A to enter new data" ' '"Press B 
to exit" 

340 IF INKEY4p ,, a" OR INKEY#="A" 
THEN RUN 

350 IF INKEY$="b" OR INKEY$="B" 
THEN STOP 
360, GO TO 340 

□ 


PRACTICAL COMPUTING October T 983 


163 



SHARP MZ-80B 


Basic listing 

ONE shortcoming of the Sharp MZ range 
of computers is that they are intended to 
be interfaced oniy with Sharp's own range 
of printers — and they are expensive. One 
of the advantages of the MZ-8GB is that it 
is available with an IEEE-488 interface 
which conforms exactly to the IEEE spec, 
unlike those offered by many of Sharp's 
rivals. This feature makes the MZ-80B a 
reliable instrument controller. 

In this role it is clearly an easy matter to 
attach any low-cost printer to the IEEE 
bus to provide a convenient hard-copy 
medium for test results, etc. It would be 
convenient to list Basic programs in the 
same way. Unfortunately, the List 
commands provided in Sharp's Basic 
dump either to the screen or on to the 
printer interface if it is present. 

The program by Jack Hale of 
Manchester overcomes this limitation 
when appended to an existing Basic 
program. It will list the program via the 
IEEE bus on an Epson MX-82 printer. It 
may be modified to suit other printers by 
changing the control characters in the 
WRT statements. 

Rem lines are detected and printed in 
double-width characters centred in the line 
to form titles. This facility may be 
removed if not required bv changing line 
61200 to 

WRT 4, OPS 

and omitting lines 61230 to 61300. 

It is convenient to position the listing 
routine at the end of the Basic program, 
hence the high line numbers. Listing of 
this routine may be suppressed so that 
only the main program is listed changing 
line 61500 to 

IF PEEK (K + 2) 4- PEEK £K + 3) * 256 
<60000 THEN J = K:F1 = 

OiGOTO 60400 

The routine steps through the Basic area 
of memory line by line. The contents of a 
line are built up into a string OPS which is 
sent to the printer when complete, 
together with the line number. Commonly 


used Basic words are held in memory in 
token form as one or two ASCII 
characters. The tokens deciphered by 
stepping through a look-up table held in 
the interpreter. This task is performed 
using a machine-code subroutine which is 
loaded in lines 60020 to 60095. The 
equivalent Basic is unacceptably slow'. 

Listing is initiated by entering Run 
60000. To list the entire program respond 
to the prompt with 0. Responding with a 
higher number will result in that and 
subsequent lines being listed. To terminate 
the listing before the end of the program 
has been reached, press Break. 


High-resolution dump 

table 1* 

Bits 

Screen 1,0 

Screen 1,1 

11 

Red 

Orange 

10 

Blue 

Magenta 

01 

Yellow 

Cyan 

00 

Green 

Buff 


DRAGON 32 


High-resolution dump 

THIS PROGRAM by S .] Combes of Bishop’s 
Stortford, Hertfordshire works for 
PModes 3 and 4. It executes in 2.5 minutes 
although it does not use machine code, 
and dumps the screen to an Epson MX -80 
MkllL This speed improvement over the 
program by R A Shackleford, published in 
the April issue of Practical Computing is 
achieved by Peeking high-resolution 
screen memory and sending the values 
direct to the primer. 

In PM ode 4 the screen is stored as 192 
horizontal lines of 32 bytes. If a bit is set 
the corresponding pixel is also set. The 
printer expects the bytes to be aligned 
vertically, which means that the picture 
must be printed on its side. This is a 


Basic listing. 


60000 
60001 
60002 
60005 
60010 
60020 
60030 
60035 
60040 
60045 
60050 
60055 
60060 
60065 
60070 
60075 
60060 
60095 
60090 
60095 
60110 
60 1 30 
60140 
60160 
60 ISO 
60200 
60300 
60350 
60370 
60400 
60500 
60600 
60650 
60670 
60700 
60900 
60900 
60930 
60970 
61000 
61030 
61050 
61070 
61090 
61100 
61200 
61230 
61270 

61290 

61290 

61300 

61400 

61500 

61600 


* * * BAS IC LISTI IM3 PROGRAM * # # 


Jack Hale - UMIST - 1902 


REM 
REM 
REM 
REM 
LIMIT $FEFF 

FDR 1-65280 TO 65359: POKE LOiNEXT J 
POKESFF 1 0 f 50 : P0KE$FF 1 1 , 0: P0fcE$FF12, 255 
P0KE$FF 15,230: F0KE$FF 1 £ 5 127 


REM 

REM 

REM 

REM 

REM 

REM 

REM 

REM 

REM 

REM 

REM 

REM 

REM 

REM 


LD A.(FFOO) 
AND 7F 
LD B, 00 
LD HL, EFF02) 
LD C, (HU 
INC HL 
BIT 7, C 
JP Z , FF20 
CP, B 

JP Z.FF40 
INC h 
JP FF20 
LD (FF025 , HL 
RET 


PDKEtFF i Si 6 : F'DKE*FF 1 9 , 0 
F'0KE$FF 1 C . 42 : PflKEtFF ID, 2s FQKEtFFl E , 255 
P0KE*FF20 70 9 

P0KE$FF21 „ 35 

PDKE4FF22, 203; P0KESFF23, 121 
P0KESFF28, 202: P0KE$FF29, 32s P0KE$FF2A , 255 
PQKESFF30, 1B4 

P0KESFF31 202: P0KE*FF32, 64: PGKESFF33, 255 
P0KE4FF38, 4 

PDKE4FF39, 195: PQKE$FF3A, 32: P0KE*FF3B, 255 
POKE$FF40, 34: PGKE$FF41 , B=PQKE$FF42, 2^5 
POKE t FF47 120 1 
LIMIT *FE^F 
CONSOLE C40 

PRINT " PROGRAM LISTING" 

WRT 4,CHR*£27) , ,r A" ,CHR$ (B ) , CHR$ ( 18) , CHR* <203 
PRINT' CHRttlJ : INPUT " INPUT START LINE NO ":LS 
Js2927AsF1=0:F3=“1 
K=PEEK < J ) +PEEK < J+ 1 3 * 256 

IF PEEK (J+2) +PEEK £ J+3) *256<LS THEN J=K:GQTQ 60300 
CONSOLE C80 

K-FEEK £ J 3 4 REEK ( J + 1 3 *256: OF *= ” " 

FOR I=J+4 TO K-l 

IF PEEK 1 1 ) =34 THEN F3^F3*{~1) 

IF tFi^i 3 4 £F3=1 3 + (PEEK i I ) < 1283 THEN 0P$-QP$+CHfi$ (PEEK £ 1 ) ) : GOTO 61080 
POKE $FF02, 50: POKE $FF03,24 

IF PEEK U) =120 THEN 1=1+1 :P0KE 145: POKE 4FF03,22 

POKE 4FF00, PEEK £ I > 

USR tiFFlO) ' 

■■ 

N-FEEK £$FF08) +PEEK ( *FF09> *256 

IF PEEK (NK128 THEN K1$=KW$+CHR$ (PEEK <N> ) : N=N+i : GOTO 61000 
KW$=KW$+CHR$ (PEEK <N3 -1 283 
IF KW*="REM“ THEN FI = t 
ap$=op$+Kw$ 

NEXT I 

WRT 4 , PEEK iJ42>+PEEKU+3 3*256: " ; 

IF LE^TS(OP$ 1 33 >< n REM" THEN W&T 4, OF*:: GOTO 61400 
IF LEN (OP1T =4 THEN WRT 4. "REM" : CHR$ £ 13) ; : GOTO 61400 
FOR A=4 TO 80: IF MID* (OP* * A, 13 = " " THEN' NEXT A 
TL=LEN(QF$>-A 

IF TL#2>71 THEN WRT 4,GP$::GDIQ 61400 

WRT 4- "REM" s SPACES ( i?\ -TL^2 J /23 ; CHR* (14); RIGHTS ( □R$VTL+ 1 J ; 

PRINT PEEK < j 42 ) *FEEK(J+3) *256:" J< :0F$ 

IF PEEK EK) 4 PEEK (K+ 1 ) ><0 THEN 5=K:^1=0: GOTO 60400 
END 


High-resolution dump. 


10 PMODE 4: SCREEN 1,1 
20 FOR A = 0 TO 31 

30 PRINT #-2 ,CHR£( 27 ) ; "3 11 ;CHR£( 24 ) ; 

40 PRINT #-2 ,CHR€( 27 ) ; fl K r> ;CHR£( 191 ) ; CHR€ ( 0 ) ; 

50 FOR B = 1 TO 191 

60 P = PEEK (7680 - CB * 32 - A) ) 

70 PRINT #-2,CHR£(P) :NEXTB 
80 PRINT #-2 , CHR€( 10 ) ; : NEXTA 
90 GOTO 90 


164 


PRACTICAL COMPUTING October 1983 


welcome advantage as it allows side-by- 
side printout of page 1 and page 2 
graphics, 

PMode 3 is more complicated* Two bits 
are used for each pixel and are coded as 
shown in table 1 , Areas of red or orange 
appear black; areas of blue, magenta, 
yellow and cyan appear grey; and 
green/buff appears white. To invert the 
picture add the line: 

65 P = 255 — P 

To print both screens side by side add: 
72 PRINT # -2, GHFt£ (27); M K”; CHR£ 
(191); CHR£ (0); 

74 FOR B = 1 TO 191 

76 P= PEEK (13824 -{B * 32 -A)) 

78 PRINT # 2, CHR£ (P); :NEXT B 

It is not necessary to merge the program 
to copy the screen since the high- 
resolution screen remains in memory after 
a New or a CLoad. Note that circles 
become ellipses when dumped. They must 
therefore be given a height to width ratio 
of 0.83 when drawn. 


High resolution dump table 2. 

Line 

Function 

10 

Displays what is being printed 


on screen 

30 

Sets line spacing to 24/216 in. 

40 

Enter bit image mode for 191 


characters 

60 

Reek screen location 


NASCOM 


this SHORT routine by G Winstanley ol 
Stoke-on-Trent enables professional 
standard mainframe or minicomputer 
communication via the RS-232 serial 
interface, input/output is achieved via the 
standard Nascom Uart, and connection to 
and from the Modem is to the user- 
available serial 1/0 socket* 

Using the selection links of LSW2, it is 
possible to have speed selections of 1 10,300 
and 1,200 baud. The only hardware 
modification required, and that is optional, 
is the connection of an acoustic warning 
device to bit 4 port 0QH, the unused bit of 
the keyboard port. Control-R reinitialises 
the program* 


The program has been kept short with 
the inclusion of some monitor subroutines 
and one restart instruction* The Blink 
routine maintains a blinking cursor and 
waits for input. It returns with the character 
in register A, and it is possible to detect 
whether input has occurred via serial in, or 
keyboard . One possible problem could arise 
if your host computer makes use of special 
control codes. Blink services certain control 
codes, such as Cursor Up, Down, etc. 
within itself. 

Xout performs Uart output with 
handshaking. It is only necessary to place 
the output character in location OUTP 
prior to calling. The Kbd routine prims 
a character to the Nascom screen. The Cler 
routine clears the screen and RST 28H 
prints on the screen the ASCII string 
following, up to the first null character 
OOH. " Q 



Nascom as terminal. 




1 



0010 

i ## 

NASCOM 

COMPUTER 

TERMINAL PROG . * % 



0020 

‘ROUTINES PERMIT TWO- 

WAV CO HUN I CAT I ON 



0030 

G VIA 

RS232 





0040 

; NASCOM BECOMES A PROFFESSI ONAL STANDARD 



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Winstanley OCTOBER 1982 



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PRACTICAL COMPUTING October 1983 


165 


NOTICE TO flDVERTlSEBB 


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166 


• Circle No. 194 

PRACTICAL COMPUTING October 1983 


Book review 



ALL the IBM PC BOOKS received so far are 
American, not surprising since in America 
the machine has a larger share of the 
market than in the U.K. Systems stretch 
from 16K cassette-based models used as 
home computers, to 544K models with hard 
discs used in major corporations. The range 
of IBM PC books, not surprisingly, 
matches the range of PC applications. 

At the beginners' level there arc already a 
number of books which aim to teach simple 
Basic programming. Probably the best of 
these is David A Lien's Learning IBM Basic 
for the Persona! Computer . This features 
the PC in its Charlie Chaplin disguise, and 
is illustrated with cartoons. 

David Lien is the serious, highly 
respected author of the invaluable The 
j Basic Handbook f published by 
Compusoft. However, his IBM book 
wallows in the worst excesses of the down- 
home American style. You do not so much 
read the book as sit grimacing while it talks 
off the page at you. Awwk!, Shew! , Wow! 
and Oooops! are typical of its interjections. 
Many sentences are somewhat lacking from 
a grammatical point of view and not all the 
jokey analogies strike home. 

However, the book is sound from the 
computing point of view. It contains lots of 
short example programs and all the ones I 
tried actually worked. The book is, 
therefore, probably a good choice if you 
can stand the style. 

Hands-On Basic for the IBM Personal 
Computer by Herbert Peck ham is a 
machine-specific version of a previous 
book, Basic: A Hands-on Method , with 
graphics and sound sections added. The 
style is much more serious than in Lien's 
book. It is text book y, perhaps because 
Peck ham used to be a professor at Gavilan 
College. Each chapter has about seven 
sections: objectives, discovery exercises, 
discussion, program examples, problems, 
practice test. It could be used in a classroom 
or for self study, but it is not as 
informative, as readable, or as easy to dip 
into as Lien's volume. 

Basic for Business for the IBM Personal 
Computer is also organised like a text- 
book, complete with ruled blank pages for 
you to write answers to set exercises. It is 
not a particularly entertaining book, but 
Alan Parker has managed to write in a 
straightforward way with as little jargon as 
possible. It should therefore be accessible 
to the average small businessman. The 
main topics covered are calculation, data 
entry and file keeping, though there is also 
a chapter on using VisiCalc. 

The illustrations include a lot of flow- 
charts and sample runs of programs. Many 
of the programs included are quite long but 
excessively well documented, and do fairly 
useful things like sorting or writing 
receipts. Naturally all the examples and 
analogies are businesslike. While the 
thought of businessmen running their 
companies on home-written Basic soft wa re 
fills me with horror, at least working 
through the book would give them some 


idea of how to evaluate packaged software. 

IBM Data Files : A Bask Tutorial is like 
Basic for Business , only more so. The 
question-and-answer bits are no more than 
quick quizzes — no bad thing — and the 
text is even easier to follow. It contains a lot 
of sensible hints and tips that obviously 
come from experience because they only 
occur to people who have tried to explain 
computing to half-wits. 

On the other hand, as well as illustrative 
examples the book also contains some very 
long useful programs. A Home Inventory 
System, for example, comprises 18 pages of 
listings and the author shows how it could 
be converted into a back-order system for 
small business use. The programs are 
modular, logical and well documented; 
they look as though they should work. So 
although IBM Data Files sounds more 
limited than other works, it is as 
educational and probably more useful than 
its rivals. 

IBM Basic for Business and Home starts 
right at rock bottom with, “What is a 
Computer?, What is ROM?” and similar 
questions. The answers are very short so the 
book moves at a fast pace. The main part of 
the book is a guide to Basic keywords, 
which provides shorter and simpler 
accounts than are found in IBM’s own 


manuals. The last part of the book deals 
with practical programming and then there 
are some very useful appendices — lists of 
commands and such like. 

What the total package provides is a sort 
of potted version of the manuals, so the 
beginner can actually start computing more 
or less straight away. The book is unlike 
others reviewed earlier in that the author 
assumes the use of a proper PC set-up, 
including disc drives and a printer. He 
appreciates that most of the time users will 
be running packaged software. Ii is a 
sensible and useful book, which IBM ought 
to pack with its machines; it would 
certainly save their dealers more than its 
cost in time. 

For people who just want Basic 
programs to type in there are two volumes 
on offer. Some Common Basic Programs 
for the IBM Personal Computer is ihe 
familiar Osborne/McGraw-Hill book. It is 
available in other editions for other micros 
including Pet, Atari, TRS-80 and the Apple 
II. There are 76 programs in all, which fall 
into four main categories: finance, maths, 
statistics and utilities. Examples include the 
usual interest-rate calculations, angle 
conversion, binomial distribution and 
sorting. 

However, having reviewed the Atari 
version of this book in Practical 
Computing a few months ago 1 have two 
(continued on next page} 


PRACTICAL COMPUTING October 1983 


167 


Book review! 


(continued from previous page ) 

comments to make. The conversion of the 
programs to the specific machines shows 
the minimum of effort. Things like 
function keys, error trapping, graphics and 
sound are ignored. Also, before you buy 
the book think about whether you really 
need the programs. 

The second book of programs, Useful 
Basic Programs for the IBM PC , is about 
hall as big. It contains 65 programs 
organised into seven chapters and three 
appendices, and covers the usual topics 
such as maths, home finance and data 
analysis. Most of the programs are only 
about 20 lines, half a page, long and again, 
unless you are an absolute beginner, you 
could probably write them just as easily 
yourself. 

There are a number of books which deal 
with operating the IBM PC in general 
without being tied to Basic, though of 
course Basic programming is a major 
feature of most of them. IBM Personal 
Computer: An Introduction to 
Programming and Applications is aimed at 
novices, and about 80 percent of the 
content is about Basic. In most of the book, 
however, the focus of attention is not on 
the language itself but on applications, such 
as, filing, graphics, word processing, games 
and science. 

One version of the book comes packed in 
a box with a disc containing all the 
programs. As you might expect in a 
beginners 1 book, however, the level is 
pretty trivial. Overall the book seems 
adequate, though it is hard to enthuse over 
it. Perhaps I was just put off by the Popular 
Computing review quoted in large red 
letters across the cover: “ ... you should 
definitely buy [this] book ... ”. It would 
not be my first choice. 

Using Your IBM Personal Computer is 
Lon Poole’s effort. He has been involved in 
the production of books for other machines 
including the Apple II User's Guide and 
Your Atari Computer , which is much the 
best Atari book available. His IBM PC 
effort is similar in approach, and also very 
good. If you had no other documentation ' 
at all you could probably learn the PC from 
this book. It deals with setting up the 
system, discs and disc copying and even 
batch processing in part one, since this is 
where the average PC user will start. It is 
only in part two it moves on to Basic 
programming. 

Actually Poole takes some stuff for 
granted, but he is excellent on the things 
I that are not intuitively obvious, such as 
numeric strings and formatting output, and j 
things that are particular to the PC. He is , 
also very good on sound and graphics and 
working the printer. The book has some i 
useful appendices including a Basic 
summary, tables of screen characters and I 
codes, and an unusually good index. It is a j 
very useful book for someone who is new to I 
the IBM PC, but not necessarily new to | 
computing. It would be ideal for easing the 
transition from, say, a Vic-20. 

T G Lewis’s book Using the IBM ‘ 


Personal Computer is even less devoted to 
Basic. In fact, the Basic interpreter gets less 
space than using VisiCalc, and only slightly 
more than the Pascal compiler. Unlike 
Poole, however, Lewis does not assume a 
familiarity with computing. The first 
chapter is “What can computers do?’’ He 
deals with the subject briefly but 
intelligently. All through the book Lewis 
manages to produce the best kind of 
technical writing: he is specific without 
being verbose, readable without being 
patronising. 

Of course he is not without 
idiosyncrasies. No-one christened 
Theodore Gyle, who dedicates a computer 
book “To life in the Oregon hills’’, can be 
completely normal. However, he is writing 
for people with disc-based systems who 
want to do serious things and run packaged 
software, and he never loses sight of this. 

However, the discussions of VisiCalc and 
Easy writer are very good, unless you 
happen to have bought Multiplan and 
WordpIus-PC, or whatever. Also, although 
the book is illustrated with screen photos 
these are very badly taken, and the cover 
picture, supplied by IBM, is awful. 

If you really do have VisiCalc, then 
perhaps you want The VisiCalc Book for 
the IBM Personal Computer , by Donald 
Bell. It condenses a mass of instruction into 
around 340 pages. As far as I can see 
VisiCalc does not much care what it runs 
on, it always works in the same way. So 
while this may be a useful book it is hard to 
see the addition of the IBM name as much 
more than a marketing ploy. I have found 
the VisiCalc manual provides more 


information than I actually need, though 
people who want to push the program to its 
limits will be glad of the extra help. 

IBM's Personal Computer is completely 
different, and I found it valuable. It is the 
book to buy before you buy an IBM PC, 
because it provides all the technical 
information you need. It shows how the PC 
fits into IBM’s product range and how it 
fits into the micro market. It provides a full 
specification of the system with 
illustrations, plus good descriptions of the 
systems software and communications 
protocols. It also methodically evaluates 
some of the software: VisiCalc, Easywriter 
and the Peachtree series, plus a few small 
programs including games. 

The resulting volume would be useful to 
an established data processing department 
thinking ol adding PCs, or to a business 
user who is about to acquire one. Because it 
deals with warranties and sales outlets the 
book’s American origins are sometimes a 
limitation, but otherwise this is a very 
handy book to have around. 

The Executive's Guide to the IBM 
Personal Computer is clearly no ordinary 
book. The title is majestic. This ring-bound 
manual comes in a slip case like a software 
package with two floppy discs in a holder at 
the back. 

But as I started to flick through it, I had 
an overwhelming feeling of deja vu. Had I 
just seen too many IBM PC books? No, I 
really had read it before. It seems to be 
page-for-page exactly the same as Basic for 
Business , reviewed here, except that the 
discs and package inflate the price from 


£12.70 to £33.95. Q 


Basic for Business for the IBM PC by Alan J Parker. Published by Reston 
Publishing, Prentice/Hall International, £12.70. ISBN 0 8359 0355 9. 

Hands-On Basic for the IBM Personal Computer by Herbert Peckham. Published 
by McGraw-Hill, £16.50. ISBN 0 07 049178 X. 

IBM Basic for Business and Home by Robert Funkhouser. Published by Reston 
Publishing, Prentice/Hall International, £12.70. ISBN 0 8359 3018 1. 

IBM Data Files: A Basic Tutorial by David Miller. Published by Reston Publishing, 
Prentice/Hall International, £12.75. ISBN 0 8359 3026 2. 

IBM Personal Computer: An introduction to Programming and Applications by 
Larry Joel and Martin Goldstein. Published by Robert J Brady, Prentice/Hall 
International, £13.35 or £27.95 including disc. ISBN 0 89303 1119. 

IBM's Personal Computer by DeVoney and Summc. Published by Que 
Corporation, distributed in the U.K. by The Computer Bookshop, £10.45. ISBN 
0 88022 100 3. 

Learning IBM Basic for the Personal Computer by David A Lien. Published by 
Compusoft Publishing, 1050-E Pioneer Way, El Cajon, California CA92020, 
S19.95. ISBN 0 932760 13 9. 

Some Common Basic Programs: IBM Personal Computer Edition bv Poole, 
Borchers and Burke. Published by Osborne/McGraw-Hill, £12.50! ISBN 0 931988 
83 7. 

The Executive's Guide to the IBM Personal Computer by Alan J Parker. Published 
by Reston Publishing, Prentice/Hall International, £33.95. ISBN 0 8359 1809 2. 

The VisiCalc Book for the IBM Personal Computer by Donald H. Beil. Published 
by Reston Publishing, Prentice/Hall International, £13.60. ISBN 0 8359 8395 1. 

Useful Basic Programs for the IBM PC by Stanley R Trost. Published by Svbex Inc. 

£7.95. ISBN 0 89588 1 1 1 X. 

Using the IBM Personal Computer by T G Lewis. Published by Reston Publishing, 
Prentice/Hall International, £11.95. ISBN 0 8359 8138 X. 

Using Your IBM Personal Computer by Lon Poole. Published by Howard W Sams, 
Prentice/Hall International, £14.40. ISBN 0 672 22000 8 


168 


PRACTICAL COMPUTING October 1983 


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Centronics 
Tractor 
RICOH 4 

Model RP 1 300 [Sf (4K Buffer} . . . £990,00 

Flo writer (SK> PR 1 600 . £1290 

Mechanical Sheet Feeder 



DOT MATRIX PRINTERS 


OKJ* 


SEIKOSHA GP-1GQ* 


M80A.. 

El 98 

GP-100A 

£210 

M82A 

£295 

[RS232 Option), 

£63 

[I20cps Pin, Friction with R5232 & 

GP-1 OO (VIC 20) 

£230 

Centronics Parallel l/F) 


GP-250X 

£261 

Tractor,. 

£55 



MS3A.,.. 

£478 



(I20cps Friction, remcveable Tractor and 

ANADEX* 


RS232 and Centronics Parallel as 

DP 9001(A) 

....,......£1100 

standard) 


DP-9S00(L) 

£950 

M84A 

£768 

DP-S 500(A) 

£1100 

EPSON 


DP-9501 

£1100 

Ep50nRX80 llOOcps} 

£245.00 

OP-9501 (A) 

1100 

Epson FX80 [1 60cps) 

£350 00 

DP-96201A) 

,...£1150 

Epson MX 100 Type III 

£398,00 

(AJ Series are all BUFFERED MODELS 


STOP PRESS NOW IN STOCK 

NEW APPLE 11E £645 

I SIRIUS 1128K WiTH 1.2 Mb S/S DISKS £1999.50 I 

_ HP PLOTTER^ .S, HP 1 ££10 — — 

TepSOIV HX20 Briefcase computer. Weighs less than 4 tbs, 1 6K expandable. 

I 64K Rom, 32K Ram, Full size ascii keyboard. Runs on own power for 50 hours. I 
Complete Serial and RS232 interface. £375- 
| Accessories Si Software for Epson HX20 available from stock. 


SOFTWARE 


Word Processing APPLE 

Applewriler 1.1 

Applewriter 2 


Applewriler He 

Word Processing SIRIUS 

Supr Calc 

Multiplan 


Select 


£55.00 

,£85,00 

Word Processing IBM 

Wordstar 

Easy writer II.. . .. 

£285.00 
£230,00 

£245-00 

Volkwriter.. 

£149,00 

£105.00 

.£140.00 
..£149,00 
£269.00 
„ £265.00 

Mailenerge 

Easy spelter 

Super writer ,, 

......... £140.00 

£115.00 

£230.00 

£85.00 




Other Software including Microsoft, r Com soft/ BOS etc. also in stock 

GOODS FULLY GUARANTEED 
PRICES EXCLUDING VAT AND P + P, 

Comp any and Government orders accepted by phone . 
Barclaycard/ Access/ Visa accepted by phone. 

Tel.: 01-455 9823 


EXPORT ORDERS WELCOMED 


MOUNTAINDENE 
22 Cowper Street London EC2 


i Circle No. 198 

169 


PRACTICAL COMPUTING October 1983 








PRINTER STANDS * MONITOR STANDS * POWER SOURCES * DREAM-81 * PROM^R-81 


CAMEL PRODUCTS 


BLOPROM-81 

A uniquely sophisticated 

EPROM 

PROGRAMMER 

In use at various labs incl. Sinclair Research 

Eprom programmer for the 2516. 27\X single supply families, yes. I 
even the 27128 from Intel. Cheek, Read, Program + Verify all or | 
part of Eprom. 

So immensely user friendly you’ll hardly need the manual. Designed lor 
the beginner but includes a single key entry route for the profes- 
sional. Supplied as firmware, the m/e driver routine alone is worth 
more than the price of BLOPROM-81. No Personality Cards or 
other additions, just a XX8I. Several inbuilt safety features. On- 
board Vpp generation. 28pin XI! socket. Cabled connector and ex- 
tender plug. ABS ease. 

Note: Can provide up to 36 inputs or 40 outputs as an I/O £79.95 | 


NEW IN CMOS 


MEMIC L.2 


A 4KB 2532/2732 replacement in fast 
(200nSec) CMOS RAM with Lithium | 
battery backup. 12” cabled connec- 
tor. I or any system with a 24 pin I 
Eprom socket £35.95 | 


MEMIC 81.2 for the ZX81 

Faster than a Floppy. Easier than an EPROM. A 4K CMOS 
memory and Lithium battery unit. Saves programmes up to 
10 years without external power. Plug it into the ZX81 and flick a 
switch and your program is ready for retrieval. A simple PRINT 
USR . . . entry loads your program into RAM. Resides in 8-I2K but 
can bo moved to I2-I6K. Comprehensive notes 4- cxample£29.95 

CRAMIC-81-2 

Banish the Whir, Click and Try again of XX8I Systems. 

I6K CMOS RAM and Lithium battery in cabled ABS case, with expan- 
sion adaptor. 

Powersoft' the ZX8 1 when running. Resides in I6-32K. Can be used like 
an ordinary 16K but can also retain program up to 10 years. In- 
genious hardware/ software allows swopping of RAMs from pro- 
gram. £79.95 

PIO-SP 

An 8-t 8 line parallel Input/Output card which lests the Spectrum com- 
municate \s it h external systems. Rugged TTI chips used. Connec- 
tions on 8 pin sockets. Mating connectors supplied. £18.50 | 

PIG-81A 

As PIO-SP but for the ZX81 £14.95 1 

DREAM-81 

A 64k with extras. 

Full 64K Rampack with link options to disable 0-8- 16K. Plus a 28 pin 
EPROM socket for 2716/2732/2764 and even the latest 27128 from 
Intel. Fast/slow Eprom option, professionally built and tested. In an 
ABS case with an LED indicator. £69.95 

PROMER-81 

At last! A low cost reliable programmer for 2516/32, 2716/32 
EPROMS. I his i> the solution to using EPROMs instead of tape. 
Requires 4 x PP3 batteries for a regulated 25 volts. Remarkably prices 
at £19.95 

ROM-81 

Provides two 24 pin sockets for up to 8K of EPROM memory in the 
8-16K area. Eproms are permanent memory which require program- 
mers (sec above) to write to I hem. Can use 2516/32 or 2716/32 £19.95 

PRINTER/M0NIT0R ACCESSORIES 

MSB Monitor Stand for BBC micro. Sits | 
over the Becb 17” x 12” x 3.75” 


P + P £3.50 


£19.95 


PSS Standard printer stands for OKI, 
Epson etc. 15”x 12”x4.5” P + P 
£3.50 £16.951 

psl I arge model I 7 " ■ 14,5° ■ 3.75” I 
P f PC3.50 £19.95 | 


| PSC-3 for Epson MX- 100 
etc. 21” x 14” x 3.75”. 
P f P £3.50 £22.95 

ICl STOM PRINTER 
STANDS for larger 
printers P.O.A. 

1*01 Printer Output I ray lor 
II” fanfold paper P < P 
£3.50 £16.95 


UK. VA I extra. No VA I on exports P f P UK, Free 
Europe * 5° ’o — Overseas 4 I O'Vo 
UK & Worldwide dealerships available. 


• Circle No. 199 


YOUR CHANCE TO 
WIN BUSINESS 
EFFICIENCY 
PRIZES 



PRINTERS 



,actt 

sinus 1 



AND OTHERS 



30 NORWOOD HIGH STREET, 
LONDON SE27 9NR 
Tel: 01-761 0435/3323 

• Circle No. 200 

PRACTICAL COMPUTING October 1963 


170 





STEMMOS 

the 

dBASEII 



experts 

TEMMOS are one of Britain's 
leading software houses^ 
and specialists in dBase I 

TEMMOS offer a helpline for 
dBase II users 


I1TEP 

ir 

riTEr 

PITEfl 

ip 


TEMMOS wrote Autocode IT 
the only intelligent 
program generator 
for dBase II 


nTEr 

ir 


TEMMOS hold monthly 

seminars in the heart of 
London on dBase 1 1 



Please send me more information on: 


dBase il 

Autocode I _ 

dBase II User seminars 

Name: 


□ 


Company: 


Address: 




STEMMOS LTD 

1 99 Uxbridge Road 
London W1 2. 


Tel: 01-740 9444 Telex: 893003 STEM OS G 


b-1 

% 

CO 

-o 

!UU1 


- An opportunity for anyone from 
engineer to businessman to write their 
own microcomputer program. 

- And for the programmer the chance 
to write programs in a fraction of the 
time. 

Seminars: 

3, 4, 5 r Oct. 7 r 8, 9, Nov, 5, 6, 7, Dec. 


STEMMOSl 

The Key to 
successful 
softwa re 


iO 

CO 

-o 



• Circle No. 201 


>NEXT MONTH 

NETWORKS & 
COMMUNICATIONS 

The special section in the November issue deals 
with the important topic of networking and 
communications. Features range from the basics of 
local area networks to program exchange via the 
public switched telephone network, 

>RE VIEWS 

We will be reviewing the latest micro to be 
launched — but what will it be? The possibilities 
include new home, portable and business micros, 

>H0ME MICROS 
UPDATE 

With the Christmas selling-season almost upon us 
we will be looking at the state of the home-micro 
market to see what is available. Anyone who may 
be getting or giving a small micro is advised not to 
miss this feature. 

>AND MUCH MORE! 

Fascinating features in the November issue include 
a selection of one-line Apple programs — a real 
challenge to human ingenuity — and a useful 
listing of *FX calls for the BBC Micro. Plus latest 
news, fiction and book reviews, and pages 
and pages of free software in a redesigned 
more legible Open File. 


Make sure you don’t miss the November issue of 



On sale at W H Smith and all leading newsagents 
after October 19 


PRACTICAL COMPUTING October 1983 


171 







SILICON 

VALLEY 

Tel: 01-242 2803 

The best value in the city for . . . 
==>ACT 

9= sinus i 



This high speed 16 bit 
business computer from 
ACT is the best selling 
micro of its kind. 
Available from Silicon 
Valley from £2,399 or 
lease from £ 1 3 per week. 
400 programs now 
available. 


Accounting systems installed 
and supported by Chartered 
Accountants 

For these products 

• We are established main dealers 

• We give the best support 

• We give the advice 

• We supply the software 
And we are always in stock!! 

Silicon Valley has on site Chartered 
Accountants, management consultants 
specialist, computer engineers to discuss 
and recommend solutions. We offerfuli 
training and maintenance -TR Y US OU T 

THE COMPLETE 

BUSINESSMANS PACKAGE 

• Sirius 1 28K computer 

• Epson Matrix Printer 

• Exact- stock, sales, invoicing, sales 
ledger& purchase ledger 

• All cables, consumables, installation 
and on site training — £2,999 
Price may vary due to time of year. 


TORCH A 


Ripple 


Software 

D Base f I, Wordstar, 

The Last One, Vis ic ale, 
plus BOS, Peachtree, 
Padmede, Systematics, 
Viasak etc. 

For Sales, Service, 
Maintenance, Advice. 
Phone 01-242 2803 

London: Suile 104/5, 

16 Baldwins Gardens. 

London EC1N7RJ 
Manchester: 12 Lever Street 
Piccadilly, Manchester 


The Permanent Computer Show 


Is 1 

L 

1 

C 

0 

N 

■v 

A 

L 

L 

E 

Y 

^0 

M 

P 

U 

T 

E 

■ 

E 

N 

T 

R 

u 



A GOOD DEAL MADE 
A GOOD DEAL BETJER 
Tel: 01-242 2803 
Teh 061 -228 1686 
Tel: 041-638 3487 


FU LL RANGE OF PR INTERS, PAPER AND DISKETTES 


• Circle No. 246 


Professional Software 
for Apple n 



Payroll An inexpensive yet accurate, reliable and 
easily operated program. Designed for the company 
with tens rather than hundreds or thousands of 
employees, Hilderbay Payroll offers all the features of 
packages costing many times more: handles all tax 
codes, salaries and NX contributions, hourly, weekly 
and monthly payslips, summary of payments etc. Will 
also work backwards (compute gross pay and 
deductions from net pay)£60.Q0 + VAT 

Bookkeeper A simple to use bookkeeping program 
can keep several books independently. Up to SO 
analysis headings can be chosen. VAT will be 
computed where applicable and full analysis can be 
printed whenever required, “There is nothing else like 
it on the market. I couldn't do without it”. (Windfall 
Magazine Review, April 1983 p76-77) £49. 00 + VAT 


Statutory Sick Pay From April 6 all employers must 
calculate and pay SSP to their sick employees. Rather 
than keep pages of information and work to 60 pages 
of the complicated DHSS Guide you can simply operate 
the Hilderbay SSP system, A free-standing program 
that will run on Apple II, SSP will work out employee 
eligibility, linking, all possible exclusions from SSP, 
tell you the information required and supply all 
figures required by you and by law. Easily operated by 
non ^computer, non-payroll personnel, u Over all rating 
very good”. (Soft Magazine Review. July 1983pl4-17£? 
101) £70.00 + VAT 


All our Apple software is offered on 21 day money back 
approval. 


Remember - we at Hilderbay pride ourselves in the 
development of high quality professional software 
that is fully functional and with full support. Not 
fancy packaging, fancy prices or fancy names. 

For further information and availability contact your 
local dealer, or order direct from us. 

TRADE ENQUIRIES WELCOME ON ALL PRODUCTS 


Hilderbay 


Professional Software 

H ilde rbay Ltd Dept. 8X0 Parkw ay 

Regents Park London NW1 7AA 
Telephone: 01-465 1059 Telex: 22870 


• Circle No. 202 


172 


PRACTICAL COMPUTING October 1983 







There's no room for a comedy of 
errors when it comes to choosing the 
right accounting program. 

The wrong decision will produce 
a very sad clown indeed. 

You can. if you really wish, pay 
£1,000 or more for a sprawling, highly 
complicated, 4-7 disk monster, with a 
manual you can’t lift without a course 
of weight training, or understand 
without a brain transplant. 
Alternatively, for just £375, you can 
discover the unique simplicity of 


it’s fully aut omatic - which mean 
no shuffling through the program to 
find the section you need. 

it’s co m plete and self-contained 
no expensive modules to buy every 
time you need an extra function. 

it’s suitable for use on HIV, VI or 
MS-DOS machines and lias so far 
been implemented on Osborne, 
Superbraln, Epson QX-iO, Sirius, 
Victor 9000. IBM PC. BBC/Torch 7,80 
and ITT with o liters in the pipeline. 


What’s more, the SAGE 
accounting program has been 
successfully tested in hundreds of 
installations and is the only system of 
its type - is as effective in a one-man 
business as in a multi million pound 
corporation. 

Check it out and we’ll turn the 
smile the right way up. 

Return the coupon and we 
will send you more information 
and the tiame of your nearest dealer, 



SAGE. 

SAGE produces the only 
accounting program which is truly 
integrated and uses only one program 
and one dam diskette. 

• Sales and Purchase Ledgers, 

• Nominal Ledger, '* * Cash Book, 

• Journal Entries, •’[Vial Balance, 

• VAT Return, •Monthly and 
Annual Accounts. *Age Analyses, 
•Statements and Audit 'IVaii — 
accounting function you need in one 
compact and comprehensive package, 
The SAGE program is also widely used 
for Incomplete Records Accounting 
(without requiring modification). It can 
therefore be used by practising 
accountants for both functions. Its 
efficiency is built on simplicity- and its 
simplicity accounts for the price. 

The SAGE accounting program is 
easy- to -I earn and easy-to-use, with a 
short, clear and simple manual, 


IT, 

! J Pietist 1 st’rul me your H explanatory brochure, 

Cl I'lcaw amrngr fnr rm i to have u demmisiraikin. 


I tlo tiol yet own i\ computer/, turn 
c< >i rip i j i< 3 1 


:ir ; 


ippruiirujir 


\rjiiif 


hi>rihni 


umifwm 


vulress 


Brl I \ sir Softw a re for Fill t Ish B u kJ iioss 

ill)., Hmvick Crescent industrial 
(jwiiv. vfWcastle n fit m Tyne 1 . \Kfi IAS. 

Tel: 0032 76J6G$fc!«X: 53623 S AGKHL (3 

PO 


Our innovation accounts tor our price! 


• Circle No. 250 

173 


PRACTICAL COMPUTING October 1983 


THE BYTE SHOPS. MACRO 
VALUE IH MICROCOMPUTERS 

THIS AUTUMH. 


PRICES EXCl, VAT 

BBC 

MICROCOMPUTER 

AC0RN50FT IN STOCK 

BBC Micro Modem 364 00 

Microvttec 14* Colour Monitor inc. 

Cables ,.,.249.00 

12 Monochrome Monitor 115,00 

Single Disk Drive 1GQK 199.00 

Dual Disk Drive 20 OK 369.00 

Duald/s Disk D rives S 00K 619.00 

Torch ZSO Disk Pack Inc. CP/M 

Compatible Op. System 96 KRAM 780.00 

Disk Interface 95.00 

Disk Cable 15.00 

Format Disk and Doc 15 00 

Epson RX / BO 298.00 

BBC to Epson Cable 24.00 

Comes Paddles IT 30 

Selection of business, educational, graphics 

and games software ava iiabl e from 3.50 

Selection of teach yourself BBC publications 


PRICES EXCL. VAT 

PRINTERS- DAISY WHEEL 

Brother HR 1 650 00 

Diablo 6 2QR025CPS 750.00 

Diablo 6 30»0 1995 00 

Smith Coran □ TP1 475,00 


COMART PRICES EXCL VAT 

COMMUNICATOR 

Clearly the most price competitive modular 
compu ler system on I be ma rket wiih built-in 
expandability - inside and our 

irt C .cpr M From 1895 .00 ex. VAT 





PRINTERS- IMPACT 

NEW IOW ANADEX PRICES 
Anode* DP95O0A 15QCPS Mai rix Printer wilh 

Graphics, L£iw Noise 995.00 

Anode* DP9501 A As DP9500A with High 

Density Gra phics 995.00 

Anadex DP9620A 200CP5 Matrix Primer, Low 
Noise 1 00 COS in Enhanced Mode .,,.1100.00 
Anadex DPS 625AM 962 OA. Double Pass 
Correspondence Quality Made at 

50 CPS 1190.00 

Anadex WP6OQ0 Dual Mode Primer 150/130 
CPS Correspondence Quality. 200 /330CPS 
Draft and Graphics Mode. Diabto630 Protocol 

Emulation 1995.00 

Epson MX1D0FT/3 Friction and Tractor 

tOOCPS ....499.00 

Epson FX/8016GCPS 438.00 

Epson RX / BO Hew Model 289,00 


OSBORNE 

Osborne Portable Computer Buy the world s 
best selling portable business computer from 
any Byt eshap a nd well affe r you a m ossive 
discounl for payment by cash off our normal 
price. The Osborne 1 Is the personal small 
computer system that is housed in a durable 
bul lightweighl 'snap togelheti case, Feaiures 
include 64K RAM, duai double density floppy 
disk drives and full 80 col . screen. The price 
also includes Standard Software - Wordstar 
Mail merge, Supercolc, M BASIC, CBA5IG. 

CP/M: Double Density/ 60 Column 
Version 1095.00 


COMART 

COMMUNICATOR 

Z80 A MODULAR SYSTEMS 

Como rt CPI 00 ‘Communicator’ Micro 
Computer Z80A Processor, 64K Byte Memory, 
Dual " Floppy Diskette Drives each sloring 

390K Bytes of Data. Dual Serial and Parallel 
Ports lOSksi SI 00 Bus. CP/ M Version 2 

included 1895.00 

Cbm art C P2 00 os CPI 00 except 0 uai 7 90K 

Byte Diskette Drives 2195.00 

Co mart CP 500 as CPI 00 except one 790K 
Byle Diskette Drive and one 5" Winchester 
Drive having 4. 8M Bytes of Formatted 

Doles 2995.00 

Co mart CP520 as CP 100 except one 790K 
Byl e Diskette Drive and one 5" Winchester 


Came rt CPI 502 As CPI 202 excepl 1 x 790K 
Byte Diskeite Drive and 1x5" Winchester Disk 
having 5M Bytes of Formatted Data with 256 K 

Byre Memory 3545.00 

Camarl C PI 522 As CPI 20 2 except 1 x 79QK 
Byte Diskette Drive ond 1 * 5" Winchester 
Disk having 19M Bytes of Formatted Data with 
25 6K8yte Memory 4545,00 

COMART CP 520MP 
MULTIPROCESSING— 
MULTI-USER SYSTEM 
PACKAGE 

The CP520MP is the new top 
specification multi user/ multi 
processing introduction to the 
renowned, expandable Coman 
Co mm u nico to r seri es , Th is tru e m uni- 
processing system ol lows one 
Communicator fo be shared by up to five 
users, each having their own dedicated 
Z80A Processor ond 84 K Bytes of 
memory with no problems of system or 
processor degradation . Each individual 
workstation can run CP/ M Software in a 
true multi-user CAdOK 

environment, IpOVVO ex vat 


1*9 


Up grad e s ^Previous nc ^ Drive havi ng 1 9M Bytes of Forma tied 


Double Density Upgrade Inc Filling .... 175 

Screen Pack 80 Column Upgrade 225.00 

Screen Pock and Double Density Upgrade 

inc. Fitting 350.00 

Osborne lo Epson Cable — 24,00 

NEW* Osborne Executive with 128KRAM, 
7" amber display, plus newsDflwore , 1995.00 


BOOKS 


Very wide range of compute i 
stocked at oil shops. 

r books 


Data 3995.00 

COMART 

COMMUNICATOR 8086 
MODULAR SYSTEMS 

Co m a rt C P 1 202 Comm unicaior M ic ro 
Computer 6M Hz 8086 Processor, 256K Byle 
Memory wild Parity, Dual 5 V * w Floppy Disk 
Drives each sloring 7 90K Bytes . D uai Serial 
and Parallel Printer Ports TO Sloi SI 00 Bus inc. 
CP/ MS 6 2745.00 



TECM AR PC MATE ADD 
ON’S AND ADD IN’S FOR 
THE IBM PC 

TECM AR Winchester Share / T 0 Expa ns ion 
10M Byte, H/O with shared system adapter for 
up to 4 x IBM PC's inc, expansion 

unit 2295.00 

TECM AR First Mate. Five in one cord, 64K Byle 


IBM PERSONAL ^ m 

COMPUTER EASY WRITER II, IU5 Word Processing 

l BM PC D uai 32QK Byte Disk Drives 6 4K Byle package ......226,00 

PAM U K Keyboa rd and Screen 2477.00 FLIGHT SIMULATOR M icrosofl Trai nin g / 

IS M PC Dual 3 20K Byte Disk D rives 1 2 BK Byte Games Package 37.00 

RAM UK Keyboard and Sc reen 2820 . 00 m A1LMER GE Micro Pro Word Proc&SSin g 

I BM PC XT 1 x 320 KB Floppy Disk pi us Enhance mem . 145.00 

1 x 10 MB Hard Disk, 128 KB RAM, ASYNCH MARS Sapphire Business System 395.00 

COMMS, DOS 2 .0 , UK keyboord and “SS” 18 Is^oo dyncmid memory cord c/wsenal and parallel 

screen . 4 440 .00 M ULTI PLAN F inancio I Sprea d Sheei ....183.00 . . afl ^ aar 320.00 

IBM Colour Adopter Cord 216.00 PASCAL MI + 86 Digiial Research TECMAR Dynamic Mertiary64K Byles 230.00 

SSSffi blS SPEUSTAR Micro Pro Wo rd Processing TECMAR^Oyna.ic Memory card ^ ^ 

EjfcrMoriilorMedRes 335 | SUPEft"cAU3SC!C t I W "Ss 00 

EPSON FXaoPHimEtt inc. cable . . .478.00 Podrage 126.00 T P ECMAR High Res . colour Graphics.. ..520.00 

SOFTWARE FORTHE ISM PC VISIQALC Financial Spread Sheer ... .166.00 DAmO Dig itaite Analog ^ 950 ° 

123 Business Mnnagcfnens Package .359.00 WORDSTAR Micro Pro Word Processing 8 

BSIAMByromCammunM^ )M 0Q ^^LMERGEMicrdPrdWd.dPrd^in” 

SSr hrB * 89, ° ,Rfl ^ ...387.00 

C9 ASIC/86 Digital Research Package ... .. , . - • ■ -■■■■-■ 415.00 

Language 129.00 WS + MM + SP/ S Micro Pro Wbrd Processing 

GGP/M- B6 Digi id Research Concurrent Packag e . . - ■ — 5 1 0 ■ 00 

CP/ M Operating system 22600 Seealso CP/ M 86 software Eisi mg. 

CP/ M86 F a r IB M PC 0/ R Ope rating 
System 39.00 

CARDS OX Caxlon Database 155.00 qa MESFORIBMPC 

D BAS E ll Ashton -Tate Data base „ nrl 

PneVaae 437.00 Microsoft Adventure ,.27.00 

E AS YR LE R IUS DQtabase Pobkaae . . , 258 .00 Ad venture in seranlb .29.00 listing . 0 ur M icrose rve C enhe s I n ott m: r _ 

E ASYPLAN HER IIJS Fina ncia I planning Casino Games. 29 . QO store s can offer full main ten a nee a nd service 

p^age 161.00 Microsoft Decathlon . 29 00 tociliitestarthhlBM PCSrTecmorPCoddon s. 


Convener 295.00 

IRMA Board - 327S Emulation 696 ,00 


The above is just a small selection (ram the 60 
pluslecmor IBM PC compatible add in's and 
ad d on's a nd specie I i st inte [face s tea t we 
offer. There are date storage expansion units; 
industrial, scientific and laboratory 
interfaces; extended Input /output expansion 
cords; general support; communications ond 
software utilities. Please contact us for a Tull 


COMART MULTI USER 
CONFIGURATIONS 

CP520 MP Multi Processing Communicator 
System c/w 1 x ZSOAmainondS x Z60A 
slaves. 64KByte main memory + 5 x 64K 
Bytes, 1 x 790K Byle Diskeite Drive + 

\ x 5 11 20 Mega Byte Wi nchester D isfc Drive, 

12 Serial & 6 Parallel Interfaces. Inc. CP/M & 

Mulii processing system software £6995. 

Como rt C P 520 / M CP520 Comm unica tor 
System with 256 K Byte Memory and 6 Serial 
Interfaces Includes CP/ M and 

MP/ Mil 4995.00 

Comart CP 1525 / M CP 1520 Communicator 
with a lotal of 51 2K Byle Memory and 
10 Serial Interfaces Includes CP/ M86 and 
MP/MB6 5995.00 


BYTESHOPFORIHE PROFESSIONAL 

There are so many micro computers on me 
mantel mat choosing the right one Is tar from 
easy. And h TsiTr made any easier when you 1 find 
them cheek tty joed with cn mere* , iR-fi end o 
hosi of other etectricol equipmeni , Whoiyou 
need is someone thoT is single minded. And thdt 
means us. Byieshopsafe (old iiy dedicated to 
microcernpurers. So, noi surprisingly, we con 
otter you a wider ra nge because we soil naming 
etse . Our prices ore keener too. So ore our stflTf, 
Each a ne is an expert who ton make sure you 
gel Ihe computer fool's exactly right ter 
you - whefoo r It's a h ome micro or o £2 0 ,000 
business system. 

What's more well freely odvise you on 
expending or upgrading your system os your 
knowledge grows or your require meats change. 
While our Klcroserve Centres OWWfuf sanrice 
an a maintenance on site end of out shops- And 
our product support spnciullifs ate your 
assurance of our total com mfonent to utter sales 
service. After oil, we ore the UK's longest 
established microcompute r specialists. 


174 


PRACTICAL COMPUTING October 1983 



Com art CP500/M CP5Q0 Communicoiot 
System wiih 256 K Byle Memory & 6 Serial 
interfooes inc. CP/M& MP/ Mil ,3995.00 

COMART PRICES EXCL. VAT 

SUBSYSTEMS 

Com art C 0200 Cartridge Tape Sack- Up 

Subsystem for Hard Disk 2495.00 

Carman H D5 20 5' 1 x 20 MByte Hard Disk 
Subsystem (requires HDCONT dr con tie added 

foaCP520orCP1520) 2395.00 

Co m art H D CO NT Wi ncbesier Disk Cam rol I er f or 

2, 2 DM Byte Drives . 195.00 

Co mart FDBOO 8" Floppy Single Disk Drive 
Subsystem; Single Sided. Single Densily IBM 
3740 Compatible (requires C-iFDC) . . .995.00 


UPGRADE 
SERVICE KITS 

Wide range of factory fined 0 to IS Bi 
and floppy id hard disk upgrade kits 
a vaila ble To r c am m ii nice for sysf e m s , 


$100 BOARDS 

Contort CRAMG4 64K Byfo Dynamic RAM wElh 

Bo rvk Select,... 200.00 

Como rt CMP U Multi-Processing Add -in Cord 
with Z8QA Slave Processor, 64 K Byte Dynamic 
RAM 2X Serial fit IX Parallel interface . . , 495 .00 
Cam arl CRAM 2 56 256K Byle Dynamic RAM 
with Partly. 8 and 1 6 Bil Data. IEEE696 
Comp alible. Also supports 8 Bit Bank 

Switching ...... .550.00 

Como rtC -CPU 86 8086 Processor Card, with 
Dual Serial and Parallel Ports. Monitor in 8K 

EPROM and 4K RAM 300.00 

Comort C-IFDC intelligent Diskette Drive 

Co ni roller wi Ih Z80 A Processor 295 00 

ComortC-CPUZBQA system Processor Board 

inc I 2 Serial n Parallel Port 200.00 

Com art 4 5 104 Channel Synch /A$ynch 

Interface Board 250.00 

Cromemco IOP I/O Processor Board wiih 
280A. EPROM. RAM and C-BUS 'Oft Card' 

Interface 425.00 

Cromemco QUAD ART 4 Channel ASYNCH / 
SYNCH Interface Board (Requires IOP). .510.00 
Cromemco Single Card Computer ZB OA. SCO. 
EPROM, RAM, Serial & Parallel Ports ... 425.00 
CM EM 3 2 32K CMOS Bctltery Supported 

Memory ...550.00 

RTCl Real Time Clock Card / Prototype 
Board .150.00 

CROMEMCO 68000/Z80A 
SUPERMICROSYSTEMS 

Cromemco C5 1 02 System 1 inc. Dual 390K 
5 jr Floppy Disks, DPU. 256 KZ and 16 FDC 
Cards in 8 Slat ST 00 Card, 

Table Top Enclosure 3730.00 

CiomemcoCSI HD2E System 1 including 
Single 390K 5" Floppy Disk, 5.5M Byte 
5" Winchester Disk, DPU, MCU, 256MSU, 

16 FOG, WD12 6345.00 

Cromemco CS 1HD2 As System 1 except 

256K2Memory without MCU ... 5970.00 

Cromemco CS lHDSEasCSI HD2Ebul with 
512MSU 7090.00 

CROMEMCO SOFTWARE 
FOR 68000/Z80A SERIES 

Cromemco CRG-D Cramix Multi-User/Mulli 
Tasking (Unix Based) Operating System 44 5. 00 


Cromemco FORD Fortran 77 ... . . 445 .00 

Cromemco PAS-D ISO Pascal 445.00 

Crom e moo AS M -0 6800 0 M ac ra 
Assembler 445 00 


Cromix(CRO-D), Aft Software is available on 
5 " or 8 Jr F lop py Disks - PI ease spec ify. 

All 68000 Languages require Cromix. 


PRICES EXCL. VAT 

VDU’$& MONITORS 

Comort WY10Q Visual Display Terminal, Green 
Display. 24 x 80 and Si atus Lines, Del ached 
105 Key Keyboard with Numeric Pad. Function, 
Cursor and Editing Controls. Swivel and Till 


Display 725.00 

Comart WYSEWORD Wordstar option . .30.00 
Comort WYT 01 VDU with two Page 

Memory. 775.00 

Valkero ra ig 4 40 4 ..595 00 

Volkercraig 4404 WS 695.00 

12" Green Screen Monitor 99 00 

DISKETTES 

Byte shop 5 1 /* " Single Sided, Single 

Densily 1 ,70ea 

Byte shop 5 1 /*" Double Sided, Double 

Densily 2.13ea 

Dysan 5V* n Double Sided, Double 

Density - 4.70eo 

Dyson 8 Hf Double Sided. Double 

Density . . ........ 5. 80ea 


Full ra nge of Dysan 5 V * u Sr 8 11 Di skettes in slock 

HOME COMPUTER 
SOFTWARE 

Avoitob!eforlBMPC.VIC.8BC.2XBl. 

Spectrum . Call tor avail ability. 

CP/M SOFTWARE 

BAS COM Microsoft Basse Compiler . ... 295 .00 
BASIC-80 Microsoft Basic Interpreter . . 259.00 

B All C Micromikes Basic Language 1 20.00 

BSTAM BYRD M Software Communications 

Package* . 130.00 

BS7MS BVROM Software Communications 

Package 130,00 

C-86 D/R C Languagewilh UNIX Version 7 

Cdmpallble Run Time Library ,TBA 

CALC STAR Micropro Financial Planning 

Electronic Spread Sheet Package 90 .00 

CARD BOX Cox ten Store /Search 

System 155.00 

OBSO Digital Research Basic Compiler 323.00 

CBS6D/R Basic Compiler ,387 00 

CBABIC Digital Research Basic 

Language 97.00 

CBASiC/36 D/R Basic language 210.00 

CISCOBOlMicrafocusCOBOL 

Language* 425.00 

CQBQL-80 Microsoft COBOL Compiler ,518.00 
CP / M‘86 DISFLWR Digital Research Operating 

System 210.00 

DATASTAR Micropro Daiobase 

Package 175.00 

DBASE || Ashion-Tate Rjelalronol Darabase 

+ ZIP’ 437.00 

FI LES H AR E (Cl S) Microfocus Uti lily 250.00 
F3LESTAR MicroseCs Disk Reformatter CP/M lo 
18 M , DEC, Motorola a nd ln.ie I Formats ,110.00 

FQ R M S 2 Micraf oc us Tabl e Maker * 110.00 

FORTRAN -80 Microsoft FORTRAN 

Compiler..;., 344.00 

GBS Bylesott Generali Business System 795.00 
JNFOSTAR Micropro Database Reporter 29 5. 00 

I SI Bytesoft Accounting Package 1 095,00 

LFVEL II COBOL Mierofocus Language* 965.00 
MACRO -80 Microsoft Macro 

Assembler 149.00 

MAI LM ER GE M ic rop ro Wardprocessing 
Enhancement lo link wrlh WORDSTAR 1 145.00 
MARS Sapphire Business System* . 395,00 
MICROS! AT Eccsoft S tali si ics Package 210.00 
MILESTONE Organic Software Critical 

Path Package' . 225.00 

MULTI PLAN Microsoft Financial Planning 

Package 199.00 

PASCAL l MT + D/R Pascal language 

wilh Speed Programming Tool 323.00 

PASCAL / MT + B6 Digital Research Pascal 

Language Far 16 Bit Systems 387.00 

PEACHTREE Basic Accounting System 

per module 325.00 


.system 
[SPOTLIGHT 



IBM 

PUS |g^|; 

282o!oo 


ex 

VAT 


PEACHTREE Business Managemem System 

per module 600.00 

PE R5 ON AL BASI C D / R language* . 97 00 
PERSONAL PEARL Fear! Data Base/ 

FNI 1 190,00 

PL / 1*80 Digital Research Language* .. 355.00 
P L / 1 -86 Dig ital Resea rch Language ... 489 . 00 

REPORTSTAR Micropro Reporter 21 0. 00 

RESCUE MBS Database 295.00 

SPELLSTAR Micropro Proofreading Uli lity to link 

with WORDSTAR’ US. 00 

SUPERCALC Sorcim Financial Planning/ 
Budgeting Spread Sheel Package* .... 1 26 .00 

SUPER SORT Micropro Sort Utility 1 45 .00 

SUPiRVYZ Epic Application Control ,. .,97.00 
V MAKER 11 Lifeboat Associates financial 

Planning /Spread Sheel Package 195.00 

WORDSTAR Micropro Wordprocessing 
Package' Also available wiih Mai I merge 

andSpellsIur 295.00 

WP WORKSHOP MAC Ltd Training Guide for 

WORDSTAR or MAILMERGE 75.00 

X BASIC Xilon Language ... 185.00 

X BASIC 86 Xitan Language 250.00 

Mp ny U1 i I ities . Prog ramm i ng foals a nd Tro i ning 
Packages available. Also extensive range of 
diskette formats. Prices include configuration 
on machines supplied by ourselves. We are 
totally com mi lied io after soles service and 
future support. 

'These software packages are avail able far 
bolh CP/M and CP/M86 


ALL PRICES EXCLUSIVE OF VAT 

*BarciaycflfdYiso ft Access f | £^3 
cards taken in payment. r I 

* Shop opening hours 9-5.30, check 
individual shops far details of Saturday 
opening limes. 

* Phan e M ail Grd e rs accepted . Pleas e co ritact 
nearest shop for RP, & Delivery Rotes. Regret 


■ Some items may be sub|eci to a dollar 
surcharge if the dollar exchange rale changes 
mare than 5 cents. Prices will be adjusted in line 
with 1 he ra le prevai f i ng at 1 he time of pu rchase. 

■ Prices subject to change without notice 

E . & . 0. E , a nd are valid for the caver dote life of 
this magaiine (October 83) 
s Whilsl we carry a vosl range of stock, we 
can no! guarantee that every advertised item 
will be available in each shap. 

* AH goods are new and include faciory warranties. 

■ No refunds on opened software. 

■ Orders from Government Depts. , Colleges & 

8 FPO addresses welcome for orders above £25 , 

* Leasing & HP facilities available -apply far 
wrfuen details, 

■Detailed prices 
available on 
request. 



WHERETO FIND US: 
LONDON 

Closely siiuated to that conspicuous 
landmark the Thames TV Centre and within 
easy reach of both GT. Portland and Warren 
St. Stations, you can be assured of o high 
level of computer expertise and a warm 
welcome from Russell Jacques and 
his staff ol the London Byteshop. Opening 
hours Man-Sal 9-5.30. 


EUSTON ROAD 


GREAT 
i PORTLAND 
STREET 


Warren Si Sth 

TOTTENHAM ► 
COURT ROAD 


BYTESHOP FOR THE BUSINESSMAN 

You wo uRJnT go to a lawyer for medical advice, er 
take your tax problems id a doctor. It's just os 
illogical to la Ik computers lo anyone but a 
computer expert. 

E very Byteshop is a spec iolisi com paler store. 
In ft you will find naming but computers and 
computer people. TTi-ere is naming else to distract 
you . Every Byteshop can otiaw you* foe very latest 
pe rsonal computer system s and provide solutions 
to bom specific and specialist tequirem cats. Ward 
processing, production control, accounts 
financial planning and date; bases are jusl a tew ol 
hie most popurar applications. 

We cam also offer everything allied to micro- 
computers. such as stationery, diskettes, boards, 
ribbon s for you r prints r, boohs, tapes and prim 
wheels. 

Just os Important , you will hove me undivided 
ode ntian at □ computer expert. Du r staff have 
been trained on air our machines and peripherals 
and can give you sound a dvice and assistance 
with complete impo rtiolity. 

Even it you hove to travel □ few extra mites it will 
certainty pay lo come to the experts . 


the ELTE SHIP 

Your Specialist Comput er Centre 


LONDON 

The Byteshop, 

324 Euston Road NW13BG 
Tel: 01-3870505 


GLASGOW 

The Byteshop, 

266 Sr. Vincent Street, G2 5RL. 
Tel: 041-221 8202 


NOTTINGHAM 

The Byteshop, 

92a Upper Parliament Street, 
HG1 6LF. Tel: 0602 470576 


BIRMINGHAM 

The Byteshop, 

94-96 Hurst Street, B54TD. 
Tel: 021-622 7149 


MANCHESTER SOUTHAMPTON 

The Byteshop, 1 1 Gareway House, The Byteshop, 

Piccadilly, Station Approach , 23 Cumberland Piece, SOI 2BB, 

Ml 2GH Tel: 061-236 4737 !el: 0703 334711 

Member* ol Ihe Comort Group or Companies 

• Circle No. 248 


175 


PRACTICAL COMPUTING October 1983 






>■ 



You've tried 
the Rest 
Now try 
the Best 


FREE withEVERYTEN-PACK 
of diskettes from DISKING at 
these prices. 

The complete DISKING DATA PROCESSING 
package 


r 


DISKETTE PRICES EXC VAT 


1 • SEE 10 LIBRARY BOX 

m:: 


Value £2.50 



The NEW DISKING ‘SEE 10' Plastic Library Box, with the facility far 
seeing ALL TEN DISKS, without the usual problem of beading the 
front disks forward. We've spent the last two years designing the 
BEST library box around, you will not find anything better. 
Unfortunately the ’SEE 10' is only available in the 5W' die, 
whereas the 8" is the ordinary egly box 


★ ★ PLUS ★ ★ 



we supply the ’soft touch' DISKING Diskwnter. This pen is perfect 
for labelling diskettes, as it will not damage the delicate surface 
beneath the disk jackel. As an ordinary writing implement, it is 
superlative 

You may purchase these separately at a silly £9.90 for 50 (please 
specify blue or black ink). 

★ ★ PLUS ★ ★ 


3 - DISK DIRECTORY 




Value 99p 





The 20 page PVC bound DISKING Disk Directory, offering two 
pages per diskette for keeping Track' of what s on each diskette. 
Also inside Ibis directory, you will find a self adhesive .ndex label 
for the spine of your Library Box. 

You may purchase these separately at £9.90 for ten. 


MEMOREX 



MEMOREX - Memory Excellence 

When it comes to PRICE/PERFORMANCE, 
MEMOREX wrote the book. Their new Japanese 
media is very conservatively rated, and certification 
levels are easily surpassed m actual performance. 
Protected by a special anti- static lubricant, head 
performance and media lile is also extended. 

5VST DISKETTES 

Certified for Single OR Double Density and all with 
hub ring reinforcement. 


PRICES EXC VAT 
3481 S/Sided 46 tpi Sott Sect . , 
3483 S/Sided 4$ ipi 10 Hard Sect . 
3485 S/Sided 48 tpi 1 6 Hard Suet . 


1040 50-99 1 00+ 
£0,90 19.90 18.90 
£0,90 19.90 18,90 
£0,90 19.90 18.90 


3491 D/Sided 43 tpL Sell Sect . . . 

3493 D/Sided 48 tpt 10 tford Seel . . 
3495 D/Stded 48 tpi 16 Hard Seel . . 


£6.90 25.90 £4.30 
£6.90 25 90 24.90 
26.90 25-90 24.90 


3504 S/SLd^d 96 ipi Soil Sect 27.90 £6,90 25 90 

3505 S/SLded 96 ip: iO Hard Sees . . . 27.90 £6,90 25.90 

3506 S/Stded 96 ips !6 Hard Seel . . 27.90 £6.90 25.90 


3501 D/Sided 96 tpi Soft Sect 

3502 D/Sided 96 tpi 10 Haid Sect . . . 

3503 D/Sided 96 tpi 16 Hard Seel . . . 


94.90 33.90 32.90 

34.90 33.90 32,90 

34.90 33 90 32,30 


48 ipi suitable Jot 35 and 40 track operation 
96 ipi suitable for 77 Pi 00 track operation 


^'DISKETTES 


PRICES EXC VAT 

3064 S/Sided 5/Dens, Soft Sect 

3015 S/Sided S/Dens. 32 Hard Sect 


3090 S/Sided D/Dens. Soil Seel .... 

3091 S/Sided D/Dena. 32 Hard Sect . 


3102 D/Sided D/Dens. Soft Sect. . 
3105 D/Sided D/Dens. 32 Hard Sect , 


10-40 50-90 100+ 
29-99 £2,90 21,90 
23.90 £2.90 £1.90 


Datalife 





DATALIFE by Verbatim - With Five 
Year Warranty 

VERBATIM have not became the World's favourite 
floppy disks by accident. Perfect magnetic media is 
their stock in trade, and to prove it they now offer an 
unconditional FIVE YEAR warranty on all DATALIFE 
products. 


5 W" DISKETTES 

Certified for Single OH Double Density, and all with 
hub nng reinforcement, 

PRICES EXC VAT 10-40 50*90 1QG+ 

MD525-01 S/S 48 tpi Soft Sect £2,90 21.90 20,90 

MD5254Q S/S 48 ipi 10 Huid Sect . £2.90 21.90 20.90 

MDS25- 16 S/S 48 ipi 1 6 Hard Sect 


MDS50-01 D/S 48 tpt Soft Ssct . . 
MD550- 10 D/S 48 tpt 30 Hard Seel . 
MD550 ■ 16 D/S 48 tpi 1 6 Ha rd Seel 


MD577-0I S/S 96 tpi Sail Sect . . . , . 
MD577- 10 S/S 96 1 pi 1 0 Ha rd Sac! . 
MD577 -16 S/S 96 ipi i 6 Hard Seel 


22,90 21,90 29 90 


29,90 21,90 £7,90 

29.90 23.90 £7-90 

29.90 £3,99 £7.90 


2B.90 27,90 £6.90 
28.90 27,90 £6,90 
28.90 27,30 26,90 


MO557-01 D/S 96 Ipi Soft Sect . , 

MD557- 10 D/S 96 tpi 10 Hard Sect . 
MD557 • 1 6 D/S 96 tpi i 6 Hard Sect . - 

49 tp; suitable for 35 or 40 track operation 
96 tpi suitable for 77 or 80 track operation 


36.90 35.90 34.90 
36,30 35.90 34 90 
36.90 35.90 34.90 


£6.90 25.90 £4.90 
£6.50 25.90 £4.90 


32.90 31.90 30.90 
32.90 31.99 30 90 


-A 


B" DISKETTES 

PRICES EXC VAT 

FD34-9000* S/S S/Dens Sot! Sect .. 
fD32-900Q* S/S S/Dens. 32 Hard Seal 


f 034 -8000 
FD32-SCQ0 


S/S D/Dans. Sail Seel 

S/S D/Deru 32 Hard Seel . 


DD3+4S01 D/S D/Dens. Safi Sec! .. 
DD32-4000 D/S D/Dens. 32 Hard Sect . 
*Far critical applications 


J0-4O 50-90 100+ 

31.90 30.90 23,90 

31.90 30.90 £9.90 


31.90 30 SO 29.90 
31,00 30.90 £9.90 


36.90 35 30 3+90 

26.90 35.90 34.30 


DISKETTE CARE AND MAILING 

The NEW DISKING 


DISKING SUPER PROMOTION 


< 



With every TWO ten Packs of any S 1 ^" or 8" disks by 
Maxell. Datalife, Memo rex or Dyson purchased at these 
prices we will pack a FREE’ Cheque Book Cover. 

Order FOUR Ten Packs and you will receive two Cheque 
Book covers and so an. 


Thus slier ends 3lsl December 1983. 


0 


t-sWWvM 

^ tJE« 
lo^ 

PRICES 



SUPERMAILER' 

' %m£ 


(5 W only) 


DISK DRIVE HEAD 
CLEANING KITS 



We re fed up with being asked whether our disk drive 
head cleaning kit actually works. So here's the proof > 

' r ^ 


* COPYRIGHT DESIGN - Unlike the rest, this ingenious 
mailer has a flute crossing actifcn when folded, 
resulting in a virtually unbendable mailer 


r 


* CAVERNOUS CAPACITY ■ will lake, one, two, 
three or even four diskettes WITH envelopes. 


L - 


* FULL INSTRUCTIONS - Each DISKING 
'SUPERMAILER' is printed with full instructions and 
comes complete with addressing/sealing label. 


.A: 


Can you really risk that breakdown? 

CK5 lor 514" disk drives . . 14.90 

CK8 for S ' disk drives . 14,90 


* PACKED IN 100'S - For convenience 

1 PACK 2 PACKS 3+PACKS 

24.90 22.90 10.90 


>■ 

DISKING - RESPOND 

A3! tree gifts- aEEeied at any time by 
DISKING are subject to 
crvciiSabrlity. DISKING reserves the 
right to substitute Ofly similar 
oil emotive item or withdraw the 
offet without notice. 

Nervous of mail older? Fed up with "'allow 28 days for delivery"? Dubious of quality? Of course 
you axe ,so what's new? DISKING STOCK ABOUND 50,000 OF THE WORLD S FINEST DISKETTES 
- That's what! Ask any of our i 000's of customers, we ship inside 4 WORKING HOURS! 

They've also discovered this in Norway, Sweden, Belgium, Germany, Malta, Greece, France, 

Israel, Bahrain, South Africa, Malawi etc. 

Whether you wai)t 1 or 100 Ten-Packs - Were waiting. 

Call Joan or Roger on 0428 722563. ACCESS, VISA & DINERS cards welcome. 





50,000 diskettes normally in stock 
most orders shipped inside 4 hours. 


DISKING INTERNATIONAL 

FREEPOST, L1PHOOK, HANTS GU30 7BR, UK 

TELEPHONE (0428) 722563 

TELEX 858623 Telbur G or 858393 Telbur G 




ALL PRICES PER TEN-PACK 


maxell 



MAXELL - The Gold Standard 

Maxell consistently meet or exceed all standards, 
and have am disks under conditions designed to find 
weak points and wear. They couldn't and you won't. 
These diskettes are the quietest In operation we 
know. 

5 1 /*" DISKETTES 

Certified for Single OR Double Density 
48 tpl media with hub ring 

PRICES EXC VAT 10-40 50-90 100+ 

MD1-D S/Sided 48 tpj Soil S«l 2+90 23.90 22.90 

MHl-10 S/Sided 48 tpi 30 Hard Seel . 24.90 29,90 22.90 

MH ] - 5 6 S/S=rfed 48 tpl 1 6 Ha/d Sect .24 .90 23. 90 22 . 90 

MD2-D D/Sided 48 ip Soft Swt . . 32.90 3 1.90 30,90 

MH2-10D D/Sided48ipi lOHaidSeci 32,90 31.90 30.90 

MH2-ISD D; Sided 48 IptlSHotaS^t 32,90 31.90 30,90 


Dysan 

m/CQRPQRATm 



- 


MDl-DD 

MD3-DD 


S/Sided 96 tpi Soft Sect 
D/Sided 96 Spi Soft Sect 


32.90 31.90 30.90 
42 90 41.90 40.90 


8" DISKETTES 

PRICES EXC VAT 

fD 3 - 128 S/S S/Dan&. Soli Seel . 
FH 3 '32 S/S S/D b ns. 32 Hard Sect 


10-40 50-90 100+ 

29.90 23.90 27.90 

29.90 29.90 27,90 


FDLXD S/S D/Dens. Soft Sect . . . 34,90 33.90 32.90 

FH] '32 D S/S D/Dens. 32 Hard Sod . 34.90 33.90 32.90 


FD2-XD 

FH2-32D 


D/S D/Dans, Sett Sect. 39.90 39.90 37.90 

D/S D/De ns. 32 Hard Sect 39.90 39.90 37.90 


DYSAN - For The Decisive 

When you think of disks you often think of DYSAN. 
DYSAN sieve the reputation for TOTAL dependability 
whatever the application. They may cost a little more 
but data is Irreplaceable. 

5 ] A ,r DISKETTES 

Certified for Single OR Double Density, and ail with 
hub ring reinforcement. 


JG4/1D 
107/ ID 
105/ID 


204/1 D 
207/ ID 


2Q4/2D 


EXC VAT 

10-40 

50-90 

100 + 

S/S 48 tip Soft Seal 

25.90 

24.90 

23.90 

S/S 48 tpi 10 Hoid Sect .... . 

25,90 

24.90 

23.90 

S/S 46 tpl 16 Hard Sect , . . 

25.90 

24.90 

23.90 

D/S 48 tpi Soil Sect . . .... 

37.90 

36.90 

35.30 

D/S 48 tpi 10 Hard Seel ■ ■ 

37.90 

35.90 

35.30 

D/S 48 tpi 16" Hard See; . . 

37.90 

30.90 

35.30 

S/S 56 Ipi Soft Seci 

30,90 

35.90 

34.90 

S/S 96 ipi 10 Hard Sect 

36-90 

35.90 

34.30 

S/S 93 tpt 36 Hard Sect 

36.90 

35.90 

34.90 

D/3 96 ip; soft sect 

46.90 

45,90 

44.90 

D/S 96 ipj 30 Hard Sect . 

46.90 

45,90 

44.90 

D/S 96 ipi 36 Hard Seal 

. 40,90 

45.90 

44.90 


48 tpi suitable for 35 Of 40 track opeitsOors 
96 IpL suitable for 77 or 80 track operation 

8" DISKETTES 

PRICES EXC VAT 

3740/3 S/S S/Dens. Soft Sect . . 

)0t/t S/S S/Dens. 32 Hard Seel 


3740/ 3D D/Dens. Sail Sect . , . 

f 0 1 / L D S/S D/Derts, 32 Hard Seel 

3740/2 D D/S D/De™. Soli Seel . 

J 0 3 /2D D/S D/Dens 32 Haed Seel 


10-40 50-90 100 + 
30.90 29.90 22.9 0 

30.90 29.90 23. 3D 

37.90 39,90 35,90 

37.90 39,90 35.90 

41.90 40.90 39,90 
41.90 40.90 39.90 


SW ■ DISKETTES 
1 -2 Pack* each pa=k 95p 
3-5 Pack* uarh pack 75p 
6-9 Pocfo trodn pack. © 6Qp 
ID+Pacb +POSTFREE* 

CLEANING KITS 

Same pailai tale at packi cl S L r 
diikf>iiB4, 10+ POST FREE 

5VNEW SEE LV ueflARV SOKES 

SEE 101-4 $j[@40*. 

SEE I0&-9oir@30p 
SEE 10 J0+@20p 


B" DISKETTES 

, 2 Packs each pack G£ i \ 5C 
3-5 Packs tail! peek, & tl 20 
6-9 Packs win pac’d £■ 90p 
•C+ Pacw +POST TREE* 

r CLEANING KITS 

Sam* pasta; ran- as packs at B 
d-skuEies 20+ POST FREE 

ff r LtfiRARV BOXES 

LBS 3 -4 alt ffl 6Qp 
LBS 5 '9 al!©4Sp 
LE9 .0+ '(HI © ’JOp 


DISKING SUPEftLUXE; DISK LIBRARY (ffl“ ONLY) 
Sartre postal tale as 5 h ' isketlei LU+ POST FREE 

DISKING SUPERMAILERS (SvrONLY) 

lOO’Pccfc CotnpkV with sealing labelsa.DD 


DISKING DISK DIRECTORIES 

DISKING DISKWR ITERS 
90'Pack E).D(t 


LOCKABLE DISKETTE STORAGE 

Ait uera-fons £2.00 each for one, £1.30 each for 2-7. 8+ posdtee 

NORMAL ORDERS - W* now w*lcom* Hour aitcLal GaTKiuriBnl ard-nn 

We oar no*? happy -c pccppl sftf otlicial orders wiir, q jr-minum *alu« .i CjOD', 1 Ham 

Go» ernnwnl Departments . NSiatilries and Local Aufccn lies We da ihn or, the Bfidesitasd:sg 

■-ho* in'volIV will hmi jetlled within thirty days *i preletatsly iesf please 

AiUmrately, you may send yoai remittance wilit yaur ard« i: you in hash 

All odim non Gavc/nmcn' bodies, -cheques with order pU-ase payat-.'- to DtSKWG 3 as* i 

large esDabhshnieiM. and cannot jaise dtfrquei w-iliioul qn inv*ic r pl*Kr*^ pen otssIfF^oire - 

you* order, and we wV|| send a pjo-iarma invoice fc/re;um, lot youe aiscpuntj qepqrnre-.Me pay 

agouti 

Atia bi*ar m mind. dial you do have la pay VAT, which will he a J elect |* th»4t- pjtc-v 
D y*u mm m any doubt. please see the ordti fcjm or iha- htpciHnf t- r.eip you w.m >c .j. 
caEctdniitsas. or leiephwe us fo dsnslahce 

CREDIT CARD ORDERS 

We weke-rne Across iMmlerrlwKjt*), Bosdajfeoidt'/lSAl & Puwis Citlb bitieriirttw^al, A tnere . 
NOcre-di! rwrd surcharge You may wnte ysut c/card Na an your craer cr telephorie the arder 
dayar mrjhl 369 days a year Yo^nnay speak lor as long as yc^. fb^’ don't i"tive gap- 
DlherwiM- o', w machine thinks you've and den i Iciqvi w five the foTiowmg derail'. 

'. Tiu- Car'dhpJdci Name. Addsess and day tm-.if iciephone number 

2 Di.f livery Address J diilerenr 

3 EirtL Class, ordinary or ipecial pasi, 

4 Your CiediS Cord Number 

5 Wjmt you wish ro Order 

6 Stare whether purchasing tigm out Generctl pjrco list oi Sudger pa-ce lisr 
'r'rj-j may leave ihe mil k> L)S M 

URGENT ORDERS 

L l you'im pesllnq ycus cider, omit lii* ward FREEPC'ST bom ciu- adare.i ana uam *41 norma; 
pastcade GU30 7Ei and da nat iotget 1c. iraoip it HRST CLASS B yew ore a Sovemmear body cti 
defused iipdiu 'NORMAL ORDERS' and oie l«3eph>onm-gyiinjr .DlFtciai;o]dei QF. ate ar.ihdividuq- 
cacampaj-.y uiinflytiH crecLl caidh'a . p'luase make a^lem that you wish to mv lor vm;f£jaf;<i) io 
be wnl la you by FIRST CLASS ?OST 

HAST CLASS RATES EXC vat MINIDISKS ft DISKETTES 

FirH TEN-PACK J t (M> i,jfl 

Seccpd and subsequent TEN.PACK l,5fl S,W 

DESPERATE ORDERS U K. 

Ymir apnora an- ■ DATAPOSt Which w;|! deliver the qae. Ja wnhir. die "J mred Kict>dorr-av^ j.ignt 
rusuolly be to re IQ am the iwxr day> pta-culed they are csdviea and pa, .1 lei irom DEStiilG by 
3 00 pit. or EKPRLSSPOST Wht:;-. wiLI dolnUi the (joodi the SAME DAY pcav-.ded ijiey gul 
urdtued and pad lor irom DISKING by 10 30 dm. and prodded yau are no rathe; ftpnh tn.aa 
Manchester 

These wnact-i p..c ie ess an gui sales arder pcocessmg ana packosira} dt? pa rime. ".is 
Please iheteiore, spgre a theught lor out -girl*, snvd rr.akt- sun- rfu-n 
a| The leqiured; goods ate m ilocl and 

p: A full pampfcmem ot manpower and trehiclw are available at DlSKfNG 


DISKETTE STORAGE 



LOCKABLE 

DISKETTE 
STORAGE 


These anti- static, AB5 piastre diskette stayage boKea come in foyi 
fitws, two tat mens disks orttf two Eot 8 ,r disks 
Ttiey have a white base with a transpar^nl smoked lockable lid, 
and hold 40 or 80 diskefies. 

They come complete with keys and didders. 

PRICES EXC VAT 

M35 40 mmldisk capacity , . . . 14,90 

M85 SO minidisk capacity . .18,90 

F40 40 8 " diskette capacity 19,90 

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DISKING SUPERLUXE 
DISK LIBRARY 

( 5 i 4 " only) ' 


LIBRARY BOXES 





TRADE CORNER 

Write or call for oui very latest Autumn J 03 TRADE PACK. 

KEENER prices than ever before, but QUALITY maintained. 

Don't buy other peoples cheap disks, they are probably batch tested and they will probably let your 
customer down. We know - we get sob stories on the 'phone daily. Every diskette that DISKING sells is 
individually certified! - for yours and our PEACE OF MIND. 

You may mix and match any of our quality diskettes so that your customers may select their favourite 
brands. This way you can be sure of pleasing everybody. 

A FREE sample unlabeUed diskette will also be enclosed, which are available in 100 bulk packs and at 
extremely keen prices fust in case you should be selling software. 

If you get any enquiries for pre -formatted diskettes, do not sweat because we can obtain most of them, 
BLANK CASSETTES are also available complete with library cases in either C- 12 or C 15 format at £39 00 
per 100, U.KLF&P £4.00. • m. -on 


< 




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7.95 

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{WOT SEE 10 Design) 

The new SEE 10 is probably Ihe besi 
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Please charge my credii card No:, 



There are some 
people who think 
that if a Printer looks 
like an Epson, 
it will perform like one. 


It won't. 


Imitation is 

the sincerest form of flattery. 
But there's only one Epson. 




Extraordinary product. 
Exceptional quality. 


Epson (UK) Limited 

Freepost, Wembley, Middlesex HA9 6BR 
Sales Enquiries; Freefone 2730 
General Enquiries: 01-902 8892 
Telex: 8814169 


178 


• Circle No, 249 

PRACTICAL COMPUTING October 1983 




word — 

Hello 

Houston, 
we have a 
problem 

Chris Naylor tells how to enhance cognitive appraisals 
with a knowledge update 


THOSE OF US who are sufficiently grey- 
haired and decrepit to remember the heady 
days of space exploration may recall a 
particular conversation which took place 
on April 13th, 1970, 

"Hey, we've got a problem here!' 1 

“This is Houston, Say again, please, 7 ’ 

“Houston, we've had a problem. We 7 ve 
had a main bus R interval.’ 1 

“Roger, Main B interval, OK. Standby 
13, We 7 re looking at it, 77 

“OK. Right now, Houston, the voltage 
is looking good . . , We had a pretty large 
bang associated with the caution and 
warning there. And, if I recall, main B had 
an amp spike on it once before," 

“Roger, Fred,” 

The exchange took place between 
Apollo 13 en route to the moon and 
ground control in Houston and the 
question that then sprang to the mind of 
the listener was: What exactly, or even 
roughly, was it all about? The “problem” 
was, in fact, that Apollo 13 had just blown 
up. There is something about the American 
way of describing things that is singularly 
impenetrable and, of late, this 
Houston-ese has been creeping into the 
computer world at an alarming rate. The 
reason is simple: nobody has anything 
interesting to say about computers, but 
everyone wants to create the opposite 
impression. 

Computers, unlike spacecraft, rarely go 
to the moon and rarely blow up. The 
things they do arc relatively common- 
place, and to state the truth of the 
situation tends to deprive the speaker of 
[he glamour which he or she may feel to be 
their due. 

The problem is most severe for 
newcomers to the game. They themselves 
cannot always see through the speech- 
opacity of the experienced computer- 
person and, worse, they have a limited 
capacity for generating opaque speech, 
which makes it difficult for them to join in 
the game. So here, by way of education, is 
a typically workaday example of how you 
should, really, explain computers. 

We wrote a program. We thought it 
would work . , , , 

J We have approached the problem with a 
real-world orientation and come to the 
following conclusions. That the problem, 
as a problem, possessed an implement- 
able structure not limited to the realm of 
theoretically possible machines but 
including, also, realisable machines. That, 
of those realisable machines, at least one 
such machine had been realised in fact 
and that a mapping of the problem from 
the abstract domain into the domain of 
this realised machine was, in fact, feasible 
given the right approach. Further, we 
believed that such a mapping would 
produce a specific solution which would 
prove to be both time and space feasible in 
the new domain. With this in mind we 
moved at once towards an implementa- 
tion-achieved type of goal in order to 
generate a suitable test pattern of theory 
against a reality-based solution.” 


. . . but the program wj too big , 

M At this stage in the process, run-time 
parameters revealed that the real-world 
implementation was, initially, alpha- 
complex to a degree that imposed 
constraints. By alpha-complex, if we may 
define a few terms, we mean that a 
minimal string representation of the 
problem with no time requirement for 
implementation was space-infeasible," 

We tried to get it to work , . . 

“The problem then became one of 
attempting for a minimax solution in which 
both the maximum alpha^complexity and 
the maximum beta-complexity were both 
simultaneously held to a minimum 
compatible with execution in the original 
problem domain. We were motivated in 
this by a belief that the problem in hand 
was, at least, semi-tractable." 

. . . and it is too slow . 

“Moving next to a space-minimal 
representation with no upper bound to the 
space requirements revealed a situation in 
which the implementation was beta- 
complex, again to an extent that imposed 
constraints of an unacceptable nature. By 
beta-complex, we naturally mean that a 
solution based on a minimal time 
requirement with an unbounded space 
requirement lead to a minimal string 
representation of the second type." 

Unfortunately the manual is not clear . . . 
"Using paperware look up we attempted 
to get a better fix on the specific sub- 
problem domain by recourse to existing 
bodies of knowledge whereupon it 
appeared that the exact sub-problem was 
one of a class not covered within the 
general domain of paperware solutions." 

. . . which is funny, because we wrote it. 
This produced some cause for internal 


■ consultation and investigation with 
| respect to paperware origination in the 
hope of pre-empting further situations that 
might be classified as similar. 7 ’ 

We could try a different problem , , . 
"Alternatively, we could go for a minimax 
solution to both the problems of alpha 
complexity and beta complexity in which 
the representing string was also current 
hardware feasible thus allowing a shift in 
the initial problem domain into the area of 
that class of problems which have 
epistemologically adequate solution 
represents! ions in current hardware 
terms." 

, . . but this one has us beaten . 

"Given the foregoing remarks, we are 
Inclined to think that the problem may 
belong to a class of genuinely hard 
problems for which no epistemologically 
adequate solution exists which Is both 
time-minimal and space-minimal due to 
the problem’s alpha-complexity and beta- 
complexity, Further, should a heuristically 
adequate representation exist then we 
doubt that such a representation would 
genuinely map on to the problem domain 
in question in a sufficiently thoroughgoing 
fashion to permit of adequate reliability. 7 ’ 

Our invoice will be with you in the 
morning. 

"Related to the foregoing remarks we 
would note that a paperware solution does 
exist in relation to the sub-problem of 
perceived fiscal constraints inherent in a 
project of this sort and that this solution is 
both space and time feasible in relation to 
yourself. And that the sort of, approximate, 
timescale envisaged is little more than a 
standard reckoning of twenty-tour hours. 
This particular aspect of the problem may 
seem semi-hard, but we assure you that it 
is, in every sense, tractable." g] 


PRACTICAL COMPUTING October 1983 


179 


Discover the Microcomputer Age 


Come along to The Northern 
Computer Fair and discover for yourself 
the excitement of the microcomputer age. 
All you need to know about personal 
computers, home computers and 
microcomputer systems for business will 
be on display at Belle Vue, Manchester 
from November 24-26. All your questions 
will be answered at the North’s premier 
personal computer exhibition. 


Enthusiasts can see the latest 
software and hardware technology in 
action, and for those new to the world of 
computers this show is a great 
introduction. Being sponsored by Practical 
Computing and Your Computer, the 
leading microcomputing magazines, you 
can be sure of value for money at £3 a 
ticket for Adults and £2 for Children 
under 16. 



— riorihem 

(omputer 

pair 

Sponsore 


Persona/ computers 
Home computing 
Small business systems 

Sponsored by: 


Practical 

Comporting 


and 


mm 


mMmmm 


so come along and bring the 
microcomputer age alive for you. 

For special party rates and further 
information contact: 

The Exhibition Manager, The Northern Computer Fair, 
Reed Exhibitions, Surrey House, 

1 Throwley Way, Sutton, 

Surrey SMI 4QQ 


Travelling to the show is also easy as 
he organisers have arranged special 
■educed-price tickets with British Rail 
which include the cost of admission. For 
urther information ring British Rail 
Enquiry Bureau on 061-832-8353 before 
slovember 11. 

The Northern Computer Fair is open 
Detween 10.00 am and 6.00 pm every day 


Belle Vue 
Manchester 
November 
24 - 26, 1983 

/ 






HAVE YOU Jt 
CONSIDERED , 
BAR CODES_ip 


Bar-codes give a speedy 
and error free means of 
data entry and provide a 
foolproof method of 
identification for any 
item or document. Typical uses include stock control, 
libraries, filing systems, security & checkpoint verifica- 
tion, point of sale terminals, spare parts identificaiton, 
etc. etc. Already most grocery products are bar-coded 
at source and many other areas of industry and com- 
merce are following. Bar-codes will soon be 
commonplace. 

APPLE 2 PET BBC micro 

A complete low cost bar-code identification system is 
available for these micros. It contains all the hardware, 
software and documentation needed to read and print 
bar-codes (using an Epson dot matrix printer). Most 
bar-code formats may be read and the system may 
easily be patched into an existing applications 
program. 

£199.00 + VAT 

*** NEW *** RS232 bar-code reader 

This new stand-alone unit decodes the bar-code and 
converts it into ASCII for transmission to the host 
computer via a RS232 port. Complete with scanning 
wand, power supply & cables. Works with virtually 
any computer. 

£385.00 + VAT 

More information on these products is available on re- 
quest. Please state your micro & area of interest. The 
decoder board is available separately to OEMs. 

DOT MATRIX & DAISYWHEEL PRINTERS 
LOWEST PRICES GUARANTEED! fxso 
EPSON FX80 RX80 
NEC 8023 STAR 
SHINWA CP80 
BROTHER TEC 
etc. etc. etc. 

Our pricing policy is 
to match or better any 
other advertiser. In addition 
enthusiastic and knowledgeable technical 
advice and backup is available to all our 
customers. Delivery is from stock to your door, often 
within 24 hours. Phone for a quote or write for full 
lists. 

ALTER (PC) 1 GREEN LANE 
WALTON ON THAMES SUR REY 
please phone before calling 
(0932)244110 3 


• Circle No. 256 


TRS-80 

VIDEO GENIE 


NEWDOS-80 
APL-80 
PASCAL-80 
FORTH (MMS) 

Details of these and over 200 other programs 
are contained in our new loose leaf 
catalogue price £1.00 (refundable) fronv- 

' A _ MICROCOMPUTER 

^XaVT applications 

|/aA\ 41 QUEEN'S ROAD 

r / V BLANDFORD FORUM 
_/ \J DORSET DT1 1 7LA 

TEL: (0258)55100 


• Circle No. 257 


Programming & 
Consultancy Service 


We can help with . . . 
Programming • system design • 
user manuals • technical training • 
hardware and software selection. 
We are at home on micros, 
minis and mainframes — in all 
major languages. 

Mike Lewis Consultants Ltd 
48 Willoughby Road 
London NW3 
tel: 01-794 3886 


• Circle No. 258 


S'Ffegpy 

ss&feT) 


ZORBA 


MICROMOOS LIP. 


fflicrefltods Ltd. 


i Circle No. 259 


Typemate 


An easy to use disc based word 
processor for the CBM 8032 
£65 inch VAT 

MCTS 

59, Ardwyn, Whitchurch, 

Cardiff CF4 7HD 

Software consultancy service 
Software written to order 
Specialists in maritime software 

Write for details 


• Circle No. 260 


NEWBURY DATA PRINTERS 

8510 from £480.00 

1550 from £600.00 

are, what other printers want to be 
Continuous Stationary 1 0OO SHTS 

11x91 plain £5.25 

1 1 xB\ plain (zip margins) £6.00 

11 x 14J plain/lined £7.00 

Min. Quantity = 1 Box (2,000 sheets) 

Contact Chris Pearce 
CDP Consultants Ltd. 

Wlcken Rd., Clavorlng, Essex CB1 1 4QT. 
(079985 617) 


THE SERIOUS PERSONS PORTABLE 
PLUS 

LUCAS LOGIC LX80 
The Low Cost 80cp$ Printer 
(A great Partemship) 

ADD 

DBASEII 

The Most Powerful Micro Database 
(Now the system Is complete) 

And you can take it anywere 
Deliveries are Immediate 

Contact Chris Pearce 
CDP Consultants Ltds 
Wicken Rd., Clavering, Essex. CB11 4QT 
(0799 85) 617 

• Circle No. 262 

“ MICRO 


we are an authorised service 
centre for Apple, Epson, 
Microwriter and most 
peripherals. Our friendly service 
staff provide a service which is 
both comprehensive and 
reliable. Call us now for repairs, 
preventative maintenance and 
contract quotes. 

Spring clean and test only 
£25.00 + V.A.T. (Central 
London). Other areas please 
call for a quote. 


01-405 9129/9125 


I 


i Circle No. 261 


• Circle No. 263 


dBASE II - by Ashton Tate is the top selling database 
package. But it from AQUA Computing Ltd, the 
dBASE specialists. 

dBASE II £375.00 

DBPlus £125.00 j 

DBFLIST £30.00 

DBAccel £50.00 

dBASE II User' Guide £22.00 

Everyman's Database Primer £ 1 2.00 

Any one of the last 4 items is FREE if you buy your 
copy of dBASE II from AQUA by July 1. 

DBPlus COMPRESEES/DECOMPRESSES dBASE II 
files to 30/40% of original size; SORTS any dBASE II 
file up to 15 times faster; MODIFIES structures easily 
- complete with manual. Pays for itself in a few 
weeks. 

Are your files scattered over several disks? DBFLIST 
compiles a master catalogue of ail your dBASE files. 
Can save you hours of searching for that 'Lost file'. 
DBAccel converts dBASE II. CMD file(s) into a single 
level format for much faster execution; Overlay control 
can be selective. Program size is limited only by 
available memory. Reduces running times by up to 
50%. 

dBASE II User's Guide is one of the best manuals on 
dBASE II; Has sold over 17,000 copies in the US; 
Written by Arthur Green, a leading US expert on 
dBASE courses. In stock now. 
dBASE II Beginner's Guide, published by Ashton Tate, 
is essential for every serious dBASE II user. 

For software products (DBASE II, DBPlus, DBFLIST, 
and DBAccel) add VAT to prices. Specify machine and 
diskette format (SD/DD, 5.25" or 8"). No extras for 
packing or postage in UK; add £5.00 for overseas. Fur- 
ther details available on all products. Pay by Cheque, 
PO, Access or VISA. Send to: 

AQUA COMPUTING LTD (Dept PCS), 10 Barley Mow 
Passage, London W4 4PH (Phone: 01-994 6477). 


• Circle No. 264 

PRACTICAL COMPUTING October 1983 






M 


icro-r*ac 


N 

YOU PAY THE 
PRICEYOU Stt 


GREAT LOW PRICES ON SUPPLIES AND 
PRINTERS 

COMPUTER SUPPLIES 

PRICE PER PAC 


5.25" FLOPPY DISKS - PAC OF 10 13 

47 

8 + 

VERBATIM SSSD 

SoltiHard Sec 

19.78 

19.26 

18.78 

DATALIFE SS00 

Soft i Hard Sec 

19.78 

19.26 

18.78 

DSOO 

SoltiHard Sec 

28.12 

27.38 

26.69 

SSQD 

SoflfHard Sec 

30.53 

29.75 

28.98 

DSQO 

SoltiHard Sec 

36.92 

35.96 

35.05 

WABASH SSS0 

SoltiHard Sec 

16.19 

15.77 

15.38 

SSOO 

SoltiHard Sec 

18.30 

17.81 

17.37 

0S0D 

SoltiHard Sec 

19.93 

19.41 

18.93 

SSQO 

Soft.Hard Sec 

21.62 

21.06 

20.53 

DSGD 

SoltiHard Sec 

23.00 

22.40 

21.84 

8" SSSD 

Soft.Hard Sec 

20.68 

20.14 

19.63 

SSOO 

SoltiHard Sec 

25.91 

25.25 

24.60 

0S0D 

SoltiHard Sec 

28.07 

27.34 

26.64 

LISTING PAPER (500 SHT PAC) 

12 

3-4 

5 * 

9.5"* 11 Side Micro Pcrfs 

4.39 

3.50 

2.75 

14.5"* 11" Music Ruled 

5.33 

4.70 

4.00 

MICRO LABELS (250 PAC) 

12 

34 

5* 

4.5"«7l16" 2 wide 

4.41 

4.05 

3.95 

Fits 9.5" Tractor Feed 




SUPPLIES FOR AIL MACHINES AVAILABLE IN BOTH 

MICRO AND 


NORMAL PACKS. RIBBONS. DISK BOXES, PRINTWHEEIS - IN 
FACT ANYTHING FOR YOUR COMPUTER CALL US NOW. 


PRINTERS AND PERIPHERALS 


Epson FX80 
Epson RX80 
Epson MX 100 


415.15 

281.40 

466.94 


AIL OTHER PRINTERS (OOT MATRIX AND LETTER QUALITY) AND 
APPLE PERIPHERALS AVAILABLE. 

PRICES REALISTIC. FOR FURTHER INFORMATION CALL OUR 
SALES OFFICE. 


REMEMBER YOU PAY THE PRICE YOU SEE. INCLUDES VAT & 
CARRIAGE 


COMPAC LTD (Micro Pac Division) 

Commerce House. Stuart Street. 
Luton LU1 5AU. Bedfordshire. 

Tel: 0582 452580. (SUPPLIES). 
0582 450557 (PRINTERS) 


E 3 


• Circle No. 265 


Programming the 

PET/CBM 

By Raeto West 


The Reference Encyclopedia for 
Commodore PET and CBM Users 
Comprehensive teaching and reference book on 
programming Commodore’s 2000, 3000, 

4,000 and 8000 microcmputcrs and peripherals. 
Many programs, chans and diagrams. 1 7 
chapters, appendices, and index, iv + 504 page 
large-format paperback. ISBN 0 9507650 0 7. 

Price in UK and Europe £ 14.90 each (includes 
post and packing). Five or more £12.90 each. 48 hour 
order turnaround guaranteed. 

From dealers and booksellers or direct: 

Trade Manager, Edward Arnold (Publishers) 
Ltd, Woodlands Park Avenue, 

MAIDENHEAD, Berks SL3 3 LX. 

Tel: (06882) 3104 
“A masterpiece" — Creative Computing 
"Essential” — Educational Computing 
"Excellent” — Jim Strasma 
“Comprehensive & Accurate” — Jim Butterfield 


Send orders and make cheques payable to: 

Trade manager, Edward Arnold ( Publishers ) Lid, 
Woodlands Park Avenue, MAIDENHEAD, 

Berks SL33LX. 

Send copy/ics Programming the PET/CBM at £14.90 

enclose choquc/PO for £ 

NAME 

ADDRESS 


• Circle No. 266 

PRACTICAL COMPUTING October 1983 


r — - DAISY-WHEEL — -1 
PRINTER 

Fantastic Value: 

• DIABLO PROTOCOLS • 18 CPS 

• BI-DIRECTIONAL • LOGIC SEEKING 

• BOLD PRINTING • SHADOW PRINTING 

• AUTO UNDERLINE • SUB & SUPERSCRIPTS 

• 100 CHARACTER WHEEL • 2K BUFFER 

• 10, 12, IS AND PROPORTIONAL SPACING 

• FANTASTIC VALUE FOR MONEY 

• ONE YEAR GUARANTEE! 

® £ 395 ..., 

Pleas* otW f.10 p A p A iniurnnrc AcM 15% VAT »o lolol 

CONSUP LTD: 


Sr-nrt ht out «'*!»• colnha u* 


LYNTAD HOUSE 
FINCK STREET 
WATERLOO SE1 7EN 
01-928 3252 


• Circle No. 267 


KINGSLEY 

40-42 Shields Road, 
Newcastle-upon-Tyne NE61 DR 
Tel: (0632 650653) 



R.G.B. 

MONITOR/TELEVISION 

AS SUPPLIED TO EDUCATION AUTHORITIES 
SPECIFICATION 

R G B. inputs (Analogue and Digital Levels) All Models 
I Volt P P. Composite Video (Remote Model only) 

Teletext Decoder available to plug into Chassis (Remote 
Model only) Remote control of Computor via Monitor. , 
(Remote Model Onlyi Sound input gives access to Audio Amp 
All Models instantly switch back to Television 
1 2" B.W. Monitor C95 + VAT 

14in. Colour Monitor. Television £227-^ VAT 

1 6in. Colour Monitor Television £255 + VAT 

1 6m. Colour Monitor Remote Television £295 * VAT 

20in Colour Monitor/Remote Television £ 3 1 5 - VAT 

22tn Colour Monitor Remote Television £340 • VAT 

26m Colour Monitor Remote Television £380 ♦ VAT 

Plug in Teletext Module £75 ♦ VAT 

Connecting Lead £5 + VAT 

Carriage and Insurance £9.50 

4 Year Guarantee Insurance £29.60 

R.G. Monitor/TV (Grundig Approved) 


• Circle No. 268 


SHOPKEEPERS 
COMPUTER SYSTEM 

Are you interested in Computer assistance in 
the running of your Business. 

Our Inexpensive Systems covers all aspects 
of your retail business. 

Have the same facts and control of your 
business as the large multipes do! Will produce 
a trail balance moments after the store is 
closed. 

Available Now 

This anarmous system for around £3500. 
Complete. No extras. 

MR RETAILER C.P.M. based programme 
£975.00. 

Dealership available 

ACCESS COMPUTERS, 

2 Rose Yard. 

Maidstone, Kent. 

Tel (0622) 58356. 


• Circle No. 269 



supercharge youx 

SUPRBRAIN 

•Much improved operating systems 
•Fast and friendly utilities 
•Powerful programming aids 
•Unbreakable security routines 
•Hi, Med 8 Lo Graphics 
•Screen handling info pack 
•Communications to outside world 
•Memory-mapped Wordstar Et Formstar 
•Video-output for extra monitors 
•Hard-disk & back-up systems 
Software from SeeDee, Phipps, Keele, McMillan 
Hardware from ICE, Fullbrook, Micronex 

Full details from: 

COMPUTER 
FACILITY 

0734 867855 

32 Redlands Road. 
READING. 

Berks. 



• Circle No. 270 


DYNAMIC SIMULATION SYSTEM 

for APPLE and CPM SYSTEMS 

* Fully Interactive 

* Powerful 

* Machine Language 

* Graphic Output 

£250 Complete 

FOR DETAILS CONTACT: 

PROCESS AUTOMATION & 
COMPUTER SYSTEMS LTD., 

50 Gosport Street, Lymington, Hants 
S04 9BE. Telephone 0590 73503. 


• Circle No. 271 



easy parking off the M56 (junc 12) • VIC 20 * VIC 64 

* BBC micros * Newbrain * Acorn Atom * Books 
\ Apple 1 1e, 1 1 1 * Dragon * Electron * Games 
. Sinclair Spectrum 

m Secondhand computers * EASY PAYMENTS „ 

• ALL ACCESSORIES SALES AND SERVICE * # 


ALL ACCESSORIES SALES AND SERVICE * 

northern Churchfield Road, 
Cheshire WA6 6RD 
TEL: FRODSHAM (0928) 35110 


wc WILL PURCHASE « ND PUBLISH YOUR PROGRAMS Call Steve Rhode, for detafe 


• Circle No. 272 

183 





Datalife 

5 Year Warranty 

by Verbatim 



Boxes of 10 Datalife Mini Disks at 
£22*50 (plus £3.95 VAT and p + p) 


* SPECIAL OFFER FREE LOCKABLE 
STORAGE UN IT WITH EVERY 5 
BOXES (50 Disks) £112.50 (Plus 
£19.75 VAT and p+p) 

To order, phone 01 -661 2060 or send 
your cheque to: ERAC Consultants 
(Southern) Ltd., Grove Flo use, 6 Grove 
Road, Sutton, Surrey SMI 1 BQ, 

Please allow 7 days for delivery. 
Personal callers welcome. 


• Circle No. 273 


BRAIN SURGEON 

Anita Electronic Services (London) Ltd 
are specialists in the repair and service of 
Superbrain I and II and associated prin- 
ters including Apple silent type, Centro- 
nic. Anadex NEC QUME, Ricoh and 
Empson. 

We also specialise in the repair of Com- 
modore and Apple computers. 

We offer a fast on-sight service or alter- 
natively repairs can be carried out at our 
workshops should you wish to bring in 
your machine. 

Maintenance contracts are available at 
very competitive prices. Trade enquiries 
welcome. 

For further information telephone or write 
to: 

MR D. WILKINSON 
Anita Electronic Services Ltd., 

15 Clerkenweil Close, 

London E.C.1. 

01-253 2444 

• Circle No. 274 

184 


Annual Maintenance 
Contracts 

1 0% of Purchase Price 

(R.R.P.) 

EXAMPLE PRICES:- 

SUPERBRAIN £200 
SIRIUS £200 

APPLE+ DRIVES £120 

YOU WILL GET:- 
24 hr Response 
Nothing else to pay 
Most Popular Micros + 
Peripherals 

Contact now:- 

S.S.W. ELECTRONICS 

Unit 8, LODGE FORGE, TRADING ESTATE 
CREADLEY RD, CRADLEY HEATH 
WEST MIDLANDS. TEL. (0384) 635237 

• Circle No. 275 


TO HELP YOU 

WIETHE POOLS 

"POOLSDATA' 1 lie suits Database 
Complete record a f all E-lyl-sh Football Loa-fJiW result*: 1 973 ■^3- ir 
The teams, scorns arwtacto.il date of over !f 0,000 matches, for 
your analyst; Simple format, with starts* analysis program* arid 
guidance nales. 

AvailoWe for Dragon Spdctmm, ZX81 . BBC, Pei. VtC Cthti- 
modoro 64 

T g jies ( 2 years dal a] C 7 . 50 
Tapes [5 years data! Cl 2.50 
Discs 15 veers data) E ! 5.P0 
'TOOLSWtNNER 1 ' Pools Predicts 
Flexible, upda table pradrCliOH program which references an 
integral Wren i database* . Predicts draws, awaysand homes. Con 
be tuned tpygurgwn unique Formula, or used m simple made. 
Available For Apple (dlsc£ SpecUumiZ X 0 1 f Tapes! 

Taqos/d-scs C 1 5. 00 

Please seed S-A,E. Tor delails. or sand chequtJS/P.O.S Hi 

SELEC SOFTWARE - — 

37 COUNCILLOR LANE 
F Y CHEADLE, CHESHIRE 

061 42E 7425 


WM 


ACCESS 


VISA 


APPLE II + AMD //e CARDS 
AT AMAZING PRICES!!!! 

New to the CIRTEGH range Intelligent Eprom 
Programmer 

Programming um/slaCuE ind-cator is conmacred ta the mam control 
cord by 2 It. ribbon cable, enabirg easy operation outside the Apple. 
Program* Snld compatible ERONVs Up to and including 37255's. 
Imdligant pfoqrammwig mode for 2764. 2712B arid 27256 
EPROM '3 drastically reduces programming) Ixinwjs (typical t-rhCS; 2764 
reduces from 450 to 70 secs., 271 2B Irani 15 to 2 mins., and 
27250 from 30 to 5 mins,! 

All operating, software is contained in Iha ROM in die programmer - 
na discs or (apes to bad. 

Add B0 column taxi to dV2 Me 
(upgradable to 1 0 or 04 K> 

B0 column text and 560 x 192 
graphics [upgradable to 64KI 
Full 64K 80 column card 

Increase the standaid 80 column 
card to 16K 

increase the standard or 16K 80 
cokimn cards to 64 K 
Run CP.'M hasud softwgro on yOur 
Apple lift Oi II 4 

PARALLEL PRINTER Centronics typo interface (echoes 

INTERFACE CARD output to Screen) 

These quality British desrgntid and manufactured cards use the laslosl 
pocking techniques (□ give high reliabnlily. improved noise Immunliy 
□ndlowtn teny niram- os Inside the Apple. 


C30.00 

E45.00 

E32.00 

C450O 


STANDARD SO 
COLUMN CARD 
1 GK BO COLUMN 
CARD 

65414 80 COLUMN 
CARD 

1 GK UPGRADE KIT 
64K UPGRADE KIT 
Z80 CARD 


tPRtJMPiflgriinxjMlr E 30.00 !{H 1 bK. Upgrade 

tftt Standiid 00 Column C 5 C .00 V & 4 K Upgrade 
We t GK EtD Column ETfi-OO Riuitcr IuLl'iTi-l.! 

he 64K BO Column EM .00 ZOO 

Postage ami packing f 1 .00 per card 
PIobso odd VAT ga 1 5% to the total' 
ORDERSi'ENQUIRIES TO: 

CIRTECH, P.O, Box 29, Dunfermline. Fife 
Telephone (0333! 729770 


* Circle No. 276 


The T.S.S, Technology Shop is now open and able to 
provide an unparalleled service for all your computer 
requirements, 

•Hsrdwarejboib new and second user equipment, 
whatever yo need at remarkable prices. 

• Sup plies — completely comprehensive range at 
unbeatable prices. 

•Service - on a national bisis with your satisfaction 
guaranteed. 

•Cnmplete used systems from El ,79 5, Used printers 
from £75, Used VDU's from E230. 

New Cm Systems from E895, Lei us be the solution lo 
your problems. Call D 1-431-31 CD now! 


• Circle No. 277 


Insure your computer 

Impact damage. fire, Iheit and transit cover 
for all your computer equipment. 

El to £1 500 Cover 28 p, a, wilh CIO excess 
£1501 to £2500 Cover £16 p a. with £ 15 excess 
£2501 1o £8000 Co v e r £ 1 6 p . a . with £25 excess 
£8001 to HQ 000 Cover £2Q p.a. wilh £25 excess 


Write or telephone today for further del ails. 

KGJ Insurance Brokers {Stourbridge) Limited 

6 Hagley Road 
Stourbridge 

■ ■ West Midlands DY8 i QK 

^ Tel: Stourbridge (STD code 03843) 

5333/2545/77391 


• Circle No. 278 


STOCK CLEARANCE SALE 


Microsoft 

BASIC 

£175 


FORTRAN 

£225 


COBOL 

£330 


BASIC COMPILER 

£202 

Micropro 

CALCSTAR 

£105 

WORDSTAR 

£210 


DATASTAR 

£155 


MAILMERGE 

£ 70 


SORG1M SUPERCALC 
ORGANIC SOFTWARE 

£135 


MILESTONE 

£170 

Ex. DEMO SUPERBRAINS 11 


“Junior 1 ’ 


£1406 

Q.D. 


£1744 

Afl prices exclusive VAT & carriage 


Microcomputer Club, PO Box 66, 
Croydon CR9 4QB 

Telephone 01 681 1885 



• Circle No. 279 




Snail Software 


MAILBAG 1 BAS 1C! DRAGON 32K 

A versatile mailing program Which amends. Mfll, pr inti, 
merges & deifies up io 1 00 filet which can be sorted and 
printed in Shy field. £10 ihc. 

DRAWER 1 COM PI LED] LVL ll VIDEO GENIE 32 K 

Ofs™ grids, circlet, arcs, graphics, (Jain ts. writes, edits and 
reverses, Vour picture can be merged with another, moved 
around ihe screen arid recorded. Easy recall to any 
program. Cample ic with manual. £25 Inc. 

ACCOUNTS (BASIC] LVL II VIDEO GE Nl E7TRS 80 4SK 
Ideal for small businesses, ar accounlenis producing 
I in ished accounts Iram inmimplete records. Full nominal 
ledger, running totals of debtors, creditors, slock 6 
capilfll assets. Weekly and quarterly cash, hank VAT & 
balance sheets. Comprehensive rnanual. £53 inc. 

Dealer enquir.es welcome. S«AI L SOFTWARE, 

2 t Ball Lsne, Ludlqw, Shropshire. SYB 1 BN. 


• Circle No. 280 

PRACTICAL COMPUTING October 1983 



If POSEIDON 
COMPUTER 
SERVICES LTD. 

| Of Hampton S.W. London Dealer 

FOR SIRIUS 1 

I DEMONSTRATION BY APPOINTMENT 
MOS T TYPES OF PRINTERS 

SUPPLIED 

BESPOKE sorm AREA SPECIALITY 


COMPETITIVE PRICES 
FULL UK DELIVERY 



=.act 


TEI 

^ sinus i 

986: 

.EPHON E: 01 -94 1 1447/5 


TELEX 8954665 GITS 


• Circle No. 281 


WORDSTAR 

ON SITE TRAINING 

Phone Mike Gardner on 
01-421 02 f>I.i 


cats 

software 


% Grimsdyke Road, 
Hatch End Pinner 
Middx HA5 4PW 


• Circle No* 282 


SCIENTIFIC SUBROUTINE 
LIBRARY 

VOLUME J — STATISTICS AM) FITTING 
FUNCTIONS 

Mean, SIX normal dkmbution, partial expeaaiion, 
Chauvenets criterion, least squares in to poly nominal 
and arbitrary function, repetitive least squares fits, 
covariance matrix, chi-squared statistic, matrix 
inversion, solution of simultaneous equations. 

VOLUME 2 - LINEAR PROGRAMMING 
Reduction of a Simplex tableau, integer 
programming, partial integer programming, 
conversational linear programming system, least cost 
mix problem. 

VO LUME 3 — F U RT 1 1 ER ST A 1 1ST I CS 
Ranking, quantiles, frequency, 2-way table, 
correlation coefficient, T, chi-squared and I- 
distributions and [heir inverses, T test, chi-squared 
test, Wikox son test, linear and multiple regression, 
A NOVA 1 - way and 2- way . 

VOLUME 4 — TRANSFORMATIONS & 

SO R UN G A LGO HIT El MS 
Fourier, FFT, Laplace, numerical integration and 
differentiation. Exchange sort, Quicksort, Shell sort. 
Tree sort. 

Manuals aid tiding fuff source i is tings Kith 
implementation notes ami documentation — 

BASIC! £25 per volume 
PASCAL 0(1 per volume 
Software in CP/M (8" SSSD) or DEC KT-ll 
(K\OI) formats — £75 +■ VAT per volume. 

CP/M TO DEC FILE TRANSER 
Software to read and write RT 1 1 format RXQ1 
diskettes under C P/M. Supplied on B° SSSE) diskette 
— £25 4 VAT. 

MICRO LOGIC CONSULTANTS LTD. 
57, Station Rd., Southwater, Horsham, 
W. Sussex. 

Telephone: 0403 731818 


• Circle No. 283 


MICROCOMPUTER INSURANCE 

Comprehensive cover at a reasonable 

premium ; 

• All Risks Cover find. Transit) — up 
to E8 r G00 for £20 

• Increased Cost of Working — to 
reinstate lost data 

• Breakdown & Derangement — 
alternative to maintenance agree- 
ment 

Write with details of equipment to: 

Geoffrey Hoodless St Associates 

Freepost (no stamp required) 

Woking 

Surrey GU21 3BR 

Tel: Woking (04862) 61082 (24 hrs) 


• Circle No, 284 



Telephone (0295) 

67551 

North Bar, Banbury. 
Oxon 0X16 0TF 


• Circle No. 285 


BBC Micro 

POOLS 

PREDICTOR 

An easy to use, very powerful forecasting program. 
Combines 6 different techniques of prediction based 
on comprehensive analysis of currant form. Can be 
"tuned 1 F , without any re-programming, lo improve 
forecasts as the season progresses. Complete with 
instructions. 

£4,99 

MAYDAY SOFTWARE 
181 , Portland Crescent 
Stanmore, Mddx HA7 1 LR 


• Circle No. 286 


MICRO ADS 

are accepted from private readers only, pre 
paid and in writing, 2Qp per vuord, minimum 
charge £2. 

Please make cheques payable to Practical 
Computing and send to Room L310, 
Quadrant House, The Quadrant, Sutton, 
Surrey SM2 5AS. 


FLOATING POINT math routines in 2716 
Eprom from Nascom systems with NAS’ 
SYS monitor. £15 with documentation. An’ 
drew Crosland, 17 Longley Lane, Hud- 
dersfield, West Yorks, HD4 6PS. 

TRANSTEC BC2, Business Microcomputer, 
2 x 400Kb disc drives, integral 12" monitor 
full detached keyboard, 10 months old! 
some discs, Cambridge (0223) 316330 
evenin gs. 

TELE VI DEO (1983) TS802H 10 MByte 
Microcomputer, Wordstar, Mailmerge, 
Datastar, Calcstar, Spetlstar, Supersort, 
Bstam, DBase2, CBasic t MBasic, Cobal, 
Pascal, PL/1, List over £8,000 accept £3 t 800 
plus VAT. Telephone 01-486 1670 anytime. 



NEWBRAIN Model 'A\ beginner’s manual 
with tape, psu., leads, manual, 7 tapes. 
£200. Ring Jonathan Reckles (0636)72156. 
Newark, Notts. 

NEWBRAIN Educational Games Tapes:- 
Mastermind, Towers of hanoi. Graphs etc. 
Ten game tape for £13.95, five game tape for 
£9.95, Contact: Robert on 01-878-3277. 

“NEWBRAIN £50 dff list price. Unused and 
in mint condition. Monitor and printer also 
available. R Davies. Crawley 33273 
(evenings)" 

BUSINESS SOFTWARE for the Newbrain 
Computer Invoice Si Credit Note; Cash 
Book; Purchase Day Book; Sales Day Book, 
Full Details & Sample Output from:- Comix- 
Micro, 16 Kneesworth Street, Royston, 
Herts. Tel: Royston (0763) 46065 

OPEN HOUSE FOR NOVICES AND 
BEYOND Choose your time — day or even- 
ing, Learn at your own pace on OSBOURNE, 
RAIR or BBC BASIC, D BASE II, SUPER- 
CALC, WORDSTAR, Graphics Introductory 
Course £45 Also evening club. Brouchure 
from: MICROCOMPUTER ADVISORY CEN- 
TRE Polytechnic of the South Bank 
Borough Road, London SE1 OAA or ring: 
01-928 8989 ext. 2468 

ASHTONTATE Dbaseil for sale, £125, in- 
cluding manual, Woking 66319. 

BBC TAPE Program Copier. Back up /multi- 
ple copies. M/code, simple to use. OS1.2, 
£4. S, Law, 105 Gill be n t Rd, Cheadle Hulme. 
Cheshire, 

XEROX 8204 Wordprocessor/computer 64K 
dual 8 J ' floppies. Super DensityKit. As new, 
£125.00 for quick sale. Telephone Mr. 
Draper 01-758 1950. (Office hours). 

SHARP HX20 including cassette drive carry- 
ing case and mains adaptor £495,00 o.n.o, 
Apple (64K) II plus green moniter dueai 
discs, includes Pascal £1,100.00, Also some 
software Visicalc 3,3 £100.00. 
Vistrend/Visipfot £150,00, Phone 01-808 
0562 evenings. 

BBC Micro (A/B) owners, develop your touch 
typing skills with Typing Trainer, Send 75p 
for listing to C. Galbraith, 65 Balfour Court 
Newfarm, KILMARNOCK 

COMMODORE C2N Cassette. Recommend’ 
ed for VIC20 and Pet. Brand new. £35.00 Tel 
02756 68152. 

BBC LINEAR Regression and Correlation 
Program, Calculates and outputs: ail sums, 
means, variances, SO, Covariance; plots 
points and two regression tines; plus 
analysis of correlation coefficient using the 
t-distribution. Cassette £5.00. David 
Wellham, 72 Monmouth Road, Dagenham, 
Essex. Tel. 593 5591. 

Si 00 BOARDS surplus to requirements, 
unused and all under half price, Hytech 
PAM Z80A 64KRAM. Measurement System 
fast set of CPU board (CPC2S10), DMA Flop- 
pydisc controller (FDC28GQ), and 64KRAM 
(DMB6400), Micropoiis FDControlB, 
Compu-time. Compu-watch, Cromen- 
coparallel I/O SPfO Telephone 02407 5611 

MARKETING POSITION SOUGHT by Post- 
Graduate Diplomat with experience in 
advertising, publicity, promotional mailing 
exhibition planning and brochure design for 
computer products Contact Geopf Pick 
BYFLEET(09323) 45174 

MZ-80K owners. Additional MONITOR will 
read ANY tape; even BASIC: moves; alter; 
verify; write; test; etc, 14 functions, £10. J. 
Leonard. JasyL Castie Drive. Praa Sands 
PENZANCE. 


PRACTICAL COMPUTING October 1983 


185 




DATA DJSH 


Data Disk (Consumables) 

St James Street 

Okehampton 

Devon 0837-4346 

COMPARE OUR PRICES 

PRINTERS 

"Star” DP5 10 Printer 
{RRP £289 + VAT) 

(SO column/ 100 CPS) 

"Star" DP 51 5 Printer 
(RRP £399 + VAT) 
nsecoiummoocps 

The New "JUKI” 61 0 Daisywheel 
(RRP £399 + VAT) 



The small Company 
with the big name 
in consumables 


OUR PRICE 

ONLY £270 Including VAT 
"Free Delivery" No Extras 
OUR PRICE 

ONLY £375 Including VAT 
"Free Delivery" No Extras 

OUR PRICE 

ONLY £375 + VAT 

"Free Delivery” No Extras 


ALL CARRIAGE FREE 

Floppy Disks by BASF 

5 1" Single Sided/Single Density ^ £1 5,00 for 10 + VAT 
Single Sided/Double Density = £22,00 for 1 0 + VAT 
Double SEded/Double Density = £24,00 for 10 + VAT 
8 " Disks and Quad Density also available 
5£" Plastic Library Cases £2.75 + VAT each 


NEW FROM FRANCE! 

LIBRARY CASES IN BROWN/CREAM. 

5T 20 - Capacity = £2,80 4- VAT 

8" 25 -Capacity = £5.75 + VAT 

Lockable Filing Cases with carrying handle Brown/Cream 

for 5*" disks x 100 capacity ONLY £18.50 4- VAT 


Other lockable filing cases; 

BY 40 -Capacity = £15.50 + VAT 
5±" 90 -Capacity = £21,95 + VAT 
8" 40 -Capacity = £22.95 + VAT 
8' 90 -Capacity = £31.95 + VAT 


Contact us for all your computer needs. Anything from 
ribbons, listing paper, labels, disks, printers etc. etc. 

Everything on mail order, enquire for our comprehensive 
price lists. 

# Free delivery on all printers and disks* 

Nominal charge for all other ranges, 

EPSON FX-80 = £42 5.00 including VAT 
EPSON RX-80 - £285,00 including VAT 
OKI MICROLINE 83a « £52 5,00 including VAT 
OKI MICROLINE 80a - £225.00 including VAT 

HOME COMPUTER TAPES 
C 1 0 - £3,50 for 1 0 including VAT 
C 15 = £3.75 for 10 including VAT 

DISK DRIVE CLEANING KITS 
5J" - £1 7,75 for 1 years supply + VAT 
8" £17.75 for 1 years supply + VAT 
5J" Basic Maintenance cleaning kits = £27.95 + VAT 
8" Basic Maintenance cleaning kits £28.95 + VAT 

LISTING PAPER 

11" xBY Single pt = £9.60 + VAT per box of 2000 
11" x 1 4 J " Single pt = £ 1 2 .40 4- VAT per box of 2000 
All other sizes available. Either plain or green lined, 

PRINTOUT BINDERS 

11" x9T £2.30 + VAT each Boxed in 10's 

Boxed in 1 0's 


Trade and Dealer Enquiries Welcomed. More Agents Urgently 
Needed Nationwide, 



A-Line Computers 42 Supp. 

A&GComputerware 42 Supp. 

ABS 48 Supp. 

ACT Computers 18,19 

Anagram Systems 13 

Anglia Computer Centre 1 01 
Apple Orchard 23 

Asco Business 1 69 

AshtonTate 39 

Atari International 145 


Advertisement index 


D 

Data Disk 186 

Data Warrior 166 

Dennison Kybe IFC 

DEgithurst 44 

Disking 176,177 

Duplex 121 

Duplex Communication 159 


B 

Beebug 

BFt Electronics 

Bits & P.C's 

British Micro 

Bromcom 

Business&Leisure 

Byte Shop 


169 

53 

70 

18,19 Supp. 
24,25 Supp. 

66 

174,175 


Edicron Engineering 
Encotel Systems 
Epson 


Fraser Associates 


148 
16.22 
34,9 1 ,1 78 


144 


Cambridge Micro Electronics 1 70 
Camden Computer Systems 52 
Chestertons 66 

Clfer Systems 9 Supp, 

Clientscene 1 70 

Comart 12 Supp. 

Commercial Data Systems 44 
Commodore Business 74,75 
Compsoft 81 

Computech 20 

Computech Systems 24 

Computer Discou nt Centre 7 7 
Computer Interface Design 44 
Comshare 30,31 

Control Data Set 84,85 

ControiUmversal 101 

Country Computers 14 Supp. 

Crof ton Electronics 52 

Crown Dust Covers 101 

Crystal Research 52 


GW Computers 40,41 

Gemini Micros 5 Supp. 

Gould Power Conversion 120 


H 

HM Systems 

Haywood 

Hilderbay 


ICS 

Icarus 

Inmac 

Inmap 

Intec 

Interface Engineering 

K 

KGB Micros 
Keyboard Hire 


6,7 Supp. 
23 Supp. 
172 


144 

42 

1 1 Supp. 
4 
97 
129 


107 


L&J Computers 
Lantech 
Lase rbug 
Laskys 

Life boat Associates 
Logica VTS 

London Computer Centre 


M 

MTech 42 Supp. 

Magus Computer Systems 1 29 
MannesmanTally 33 

Matrix Computer Engineering 38 
MayfairMicros 66 

McGraw-Hill Books 162 

MemorexUK 56 

Memotech 36,37,38 Supp. 

Micro Miracles 23 

Micro Peripherals IBC 

Microcomputer Products 1 1 1 
Micromanagement 1 32, 1 37 
Micronix 63 

Microprocessor Engineering 56 
Micropute 47 Supp, 

Microvalue 138,139 

Microware 1 46 

Mountarndene 169 

N 

Northern Computer Fair 180.181 



• Circle No. 240 


P 

Padmede Computers 

89 


Page Plus 

57 


Perfect Software 

46,47 


Pete & Pam 

51 

56 

Phoenix Technology 

144 

38 

Practical Electronics 

88 

148 

54,55 

Q 


140 

Quantum Computer Systems 28 

67 

Qume (UK) Ltd 

50 

14,82 

R 

Rair 

98 


Sage Systems 
Sanyo 

Shelton Instruments 
Shurland Computers 
Silicon Valley 
Simmons Magee 
Sinclair Research 
Sirton Computers 
Soft Option 
Sola-Banner 
Stemmos 
Sun Computing 
Swan Packaging 
Symbiotics 


41 


173 

92 

Supp, 

145 

172 

32 

9,12 

43 

153 

24 

170 

BC 

148 

71 


T 

Tabs IFCSupp, 

Tandy Corporation 17 

Texaslnstruments 25,27 

Triumph Adler 76 

Twickenham Computer Centre 

145 


01 Computers 

OEM 

OKI 

Oric Products 
Grmskirk 


36,152 
1 7 Supp, 
157 

29,30,31 Supp. 

90 


Val Warden Associates 
Verwood Systems 

W 


114 

24,56 


168 Osbourne ComputerCorp. 48,49 Watford Electronics 


186 


PRACTICAL COMPUTING October 1983 




SHINWA - CTI 


?VfCi>£ 


Micro PeiiDheraU, 69 The Street Bosino, Basin rrstnlce R(G 24 DRY 


Please send technical details, printout samples and 
local dealer details to:™ •Circle No. 241 

Name: Position 

Company: 

Address: 


Best Distributor:- 


micro 

Peripheral/ Ud 

69 The Street, Basing, Basingstoke, Hants. RG24 OBY 
TFT/ rna™ 3999 no 1 ™^ m fy. omcrci k/ipdot) n 


Best Producer — HERMES 612 

WPQ Printer 

available from around £1950 ex VAT 

★ Up to 400CPS and Word Processing 
Quality at 120 CPS 

★ 1 0, 1 2 or 1 5 CPI — programmable 
to 1/360" spacing 

★ 132 column at 10 CPI 


All now on general release - see them at 
your local dealer 


NOMINATIONS FOR 


Best Star - STAR DP 5 1 0/DP5 1 5 

Matrix Printers 

available lor around £289 and £399 ex VAT 


k 


k 


' k 


k 


k 


k 


k 


k 


k 


k 


k 


k 


80 Column (DP510), 

136 Column (DP515) 

100 CPS, Bi-Directional Logic 
Seeking 

Friction, Tractor and Roll Holder 
as standard 

Full standard features including 
2.3k Buffer 

Best Performer — 

JUKI 6100 Daisywheel 

for around £399 ex VAT 

-■ Bi-Directional Logic 

12, 15 CPI 4- Proportional 

"Drop in" Daisywheel — Triumph 
Adler Compatible 
Supports all Wordstar features 
Diablo protocols — IBM Selectric 
ribbon 

2k Buffer as standard — 

100 character Daisywheel 

Best Newcomer — SHINWA - 
CTI CP80 Matrix Printer 

available for around £289 ex VAT 

80 CPS — Bi-Directional Logic 
Seeking 80 Column 
Friction and Adjustable 
Tractor Feed 

Patented Square Needles up to 
9 x 13 matrix 

Hi-Res Graphics and Block 
Graphics 
















NEW - ZORBA 2000 SERIES 

NOWWITH FULL 9” SCREEN 



NEW MODEL 4 8 Bit Processor 

Full 80x25 9" Screen 
800KBytes Disk Storage 

NEW MODEL 8 8 Bit Processor 

Full 80x25 9" Screen 
Massive 1 .6 MBytes 
Disk Storage 

NEW MODEL 16 8 and 1 6 Bit Processors 

Full 80x25 9” Screen 
Massive 1 .6 MBytes 
Disk Storage 


All Models Include:- 

FREE SOFTWARE 

C BASIC ★ WORDSTAR * MAILMERGE ★ 
CALCSTAR 

MORE COM RATABILITY 

Read & Write the following formats:- IBM PC, 
OSBORNE, SUPERBRAIN, XEROX 820, 
DEC VT1 80, KAYCOMP & TELEVIDEO 

MORE EXPANDABILITY 

Outputs include:- Parallel, Serial & IEEE 488 


Defa//s from the Sole UK I m porter 


Sun Computing Services Ltd, 

Concorde House, St. Anthony’s Way, Feltham, 
Middlesex, TW14 0NH. 

Tel 01 890 1440 

Twx 8954428 SUNCOM G 


ZORBA is a registered trademark of MODCGMP INC. 

* Circle No. 242 


PRACTICAL COMPUTING 
Room 309H, 

Quadrant House, 

The Quadrant, 

Sutton, 

Surrey, SM2 5AS 



GREAT CHRISTMAS GIFT OFFER 

1 

More copies for jess money. That’s what you get when you take up the great Practical Computing Christmas 
subscription offer. 

i 

So, whether its a subscription for a friend with a personal computer, or that little extra something for yourself, you’ll get 
I two extra issues absolutely free of charge which means that you’ll receive 14 issues of Practical Computing instead of 12. 
And all for £1.00 less than you would normally pay! 


PRACTICAL COMPUTING: CHRISTMAS GIFT SUBSCRIPTION OFFER 

Yes, I wish to take out a year's subscription to Practical Computing at the reduced rate of £12.00 (UK) or £18.00 (Overseas) 
with the added bonus of two extra issues absolutely free of charge. 

I enclose cheque/PO to the value of: □ £12.00 UK □ £18.00 Overseas 

OR Please debit my credit card account: Expiry Date Barclaycard/Visa Access 

□ 


Account No. 


Tick 

relevant 

box 


□ 

Diners Card 
□ 


American Express 

□ 


Signed 


Date 


NAME 

ADDRESS 

1 (BLOCK LETTERS PLEASE) 


Name and address of person to whom gift 
subscription is to be sent: 

NAME 

ADDRESS 

(BLOCK LETTERS PLEASE I 


POSTCODE 

Offer Closes 23rd December, 1983 

Please return this order form with your remittance pTease to: 


POST CODE 

Registered in England 1 SI 537, Registered Office, Quadrant House, 
The Quadrant, Sutton. Surrey, SM2 5 AS. 


PRACTICAL COMPUTING, Room 309H, Quadrant House, The Quadrant, Sutton, Surrey, SM2 5AS